CANCERING: Listening In On The Body's Proteomic Conversation (PART II)

W. Daniel Hillis (During this session Hillis was asked to comment on a number of specific topics:)



On the relationship between genomics and proteomic testing What I've been talking about here is more analysis than construction. The genome is used to construct things, and I'm claiming it's not the best place for analysis of what's going on. Certainly there are times it is useful, but I don't think that's where most of the information is. In fact, it is literally true that the information that's in proteomics tells you everything that was in the genome, everything that was useful. In a sense, the genome is redundant if you have the proteomics. That's theoretical though, because the genome is digital, and we actually have it. In many ways it's enabled proteomics. Right now, when I show you that image that has the hundreds of thousands of dots on it, I can actually tell you what a lot of those things are because we know the genome; so I can actually associate many of those dots with genes, and because we have these great genetic expression tools and so on, we may know what part of the body it's in, we may know a lot about the pathways because we can do knock-out genes. It's a great experimental method for actually controlling what proteins get produced and so on. In many ways proteomics was made possible by genomics. It builds on top of genomics. I guess it's true in some theoretical sense that eventually you might not even bother to look at the genome if you can see the whole proteome. In practice, it's been very important. The genome is the instructions for the cell. That's very important if you want to do manipulation. If you want to actually affect the pathway, then that is the level at which you need to manipulate things. You want to knock out a gene, or modify a gene. Experimentally, being able to read and write the genome is incredibly important. But if you want to use it as a diagnostic for what's going wrong with a particular individual, it will be unusual for that information to be in the genome. On the role of gene testing in cancer Let's take somebody who has cancer. They used to be somebody who didn't have cancer, and they had the same genome. So the difference between having cancer and not having cancer is clearly not just in the genome. There's more to it than that. In fact, most of their cells aren't cancering, and they have the same genome. Cancer is a dynamic process that's happening, and it's not just in the genome. Now, there may be a specific mutation from a genome that helps explain why it happened. For instance, one of the dramatic genetic test successes has been in breast cancer, BRCA1 and 2, which are specific genes that are associated with breast cancer. They occur a lot in Ashkenazi Jews, and a particular kind of breast cancer is associated with these genes. There are many examples like this where there's a genetic predisposition to cancer, but is one of the clearest examples. The cancer isn't inherited, but that's a predisposition that is, so people that have the gene are more likely to have cancer. Let me put it in terms of the conversational analogy. That means that certain words are missing, and in that case we know there is a conversation about fixing broken DNA. We're repairing broken DNA and it's hard to describe what to do without those words. You need to discuss BRCA1 and BRCA2, and you need to use those concepts. You need to use those words in order to repair DNA in a certain way. If you don't have those words in your vocabulary, then you're unable to execute this process of repairing DNA. If those words are slightly mutated so that they're not understandable, if you slur them, or stutter them or something like that, they're won't have the desired effect. It won't always cause a problem because there may be other pathways that also repair the same defect. If the other pathways are working very well to control your DNA, it might not matter. But there is an association, and you can look at people, you can test them, and you can say, "Well, if they have this mutation, they're more likely to get breast cancer", and actually, it turns out, they are much more likely to get breast cancer. Furthermore, you know what the failure mechanism is, so there are many people who get breast cancer for completely different reasons that have perfectly intact BRCA1 and BRCA2. By the way, that same pathway, because it's a general pathway for repairing DNA, is also important for ovarian cancer because if you don't repair properly, then you're more likely to get ovarian cancer, too. It doesn't really have anything much to do with breasts other than that's where you see the symptoms of this happening, it's usually first noticed in breasts. On the application of proteomic modeling to cancer treatment The cancering metaphor does mess up our standard model of medicine, where we just take the right pill to fix a given problem. But if you think about it, the idea that you should be able to take a pill, and it should magically fix a disease, a systems disease, a failure of the system, is kind of amazing that that's even possible. The cases where it's mostly possible is where you have an invading thing that doesn't belong, like an infectious disease, and you take a pill that poisons that particular thing, like an antibiotic. There are a few cases where you're just missing one component, and you take a pill that provides the missing ingredient, and so there will be a few magic cases like that, but those are very special kinds of failure, and I don't think they'll be the typical failure in cancer. Unfortunately this whole idea of fixing a disease with a pill, while it's delightful when it works, is not very generalizable. We haven't found very many new pills lately that really cure diseases. In fact, the pharmaceutical industry is kind of broken right now because they've run out of this low-hanging fruit, a magical chemical that cures a disease. I don't think we're likely to find a lot of more those. They need a different model. The first commercial application of proteomics will be diagnostics and probably something much simpler than what I was describing before. The way proteomics will get started is by being markers for diseases that we already diagnosed, in other words, it will help support this categorization system of diagnosis. Let's say I could find a pattern of proteins expressed in your blood that said whether your colon was growing polyps in it. That would be much better than having a colonoscopy. You get a colonoscopy every five or ten years, which is now recommended — even though in one in a thousand people they create serious damage giving the colonoscopy — we still recommend that people do it because we don't have a better way of telling if you're in this kind of precancerous stage. If you could do that in your annual blood test, it would be much better. That is an example of a very early use of proteomics. Probably there would be many things like that where if you could detect breast cancer without a mammogram, or if you could do a confirmatory test of prostate cancer without doing a needle biopsy, all of these things are very invasive, and expensive, and cause a lot of secondary harm to people. On the relationship between proteomics and synthetic genomics At last year's Edge Master Class in Los Angeles, George Church and Craig Venter talked about Synthetic Genomics. Proteomics is relevant to that because it's also a tool that such researchers could use since they need to debug their synthetic genomics. When you write a computer program, the first thing you do is you try to run it, and it almost always has a bug in it, so you see what happens, and you debug it, you stop it in the middle of running, and you see what the state of the system is, and you understand what your bug is, and then you change the program. Right now George and Craig don't have the debugger. Proteomics is the debugger that they need. When they write a program and it doesn't work, which actually happens a lot, in order to tell why it's not working, they need proteomics to say, "Oh, I see, this isn't upregulating that enough, or downregulating that ... ", and that will help them debug their program and tune their program. Right now a lot of synthetic genomics is about copying a naturally-evolved program, and saying, "Okay, I can make a copy of this program, and write it, and it does the same thing", and that's interesting. It would have been very surprising if it hadn't worked. On the business of proteomics The business of proteomics had a false start a few years ago. As I said, proteomics can't be done with the techniques and tools that are sitting around a laboratory, a biological laboratory; it's not a biology problem. Unfortunately there are a lot of people who tried to do it with those tools and so there were a few companies that started up, and a lot of laboratory projects that started up, and they published a bunch of results probably prematurely, and they couldn't replicate them because, you know, the next time they ran the tests it came out differently. It was so noisy that they had to do very, very large trials. So if you have a bad instrument, then it's not going to work. Because of that, proteomics got a bad name among the venture capitalists. Probably most venture capitalists will cut and run if you say "proteomics" right now because of the problems with the tools of a few years ago. What will happen is we'll get some successes. In spite of this, there will be a few things like Applied Proteomics that get started, and there will be a few people with more vision that look at it more closely, and say, "This actually fixes the problem that they had before, because the story was right before, it was just they couldn't make it work." As soon as there is a success, then you'll see a general change in attitude. Venture capital tends to work this way. There will be lots of people investing in this area, and there will be a boom very much like there was in genomics, and sequencing. Lots of effort will go into both the technology of doing the proteomics better, as it happened with genomics, and also the application of proteomics. And again, first it will be to these diagnostics, and then it will be things like drug rescue. Billion-dollar drugs that had to be taken off the market after having had huge amounts of money invested in them because one in ten thousand people reacted badly to them. Well, if you could tell who was going to have that reaction, if you could make a test for it, and again, if you could find in a proteomic marker for what it was about, what was wrong with the dynamics of their body to cause them to have that reaction, then all of a sudden such drugs would be viable again. They could recover that billion-dollar investment. You'll see pharmaceutical companies take it up for reasons like that. That's the "safe" part pharma companies are looking for drugs that are "safe and effective", so it will help them with safe. It will also help them with "effective" because right now, if you have something that not everybody responds to then it is not effective. We've had the first examples of that already, where a drug wasn't statistically effective. But when we look again we can say, "Well, people who have this protein being expressed, it is effective." So there is a very simple case where you're looking at a single protein. This single-protein expression is a situation analogous to a conversation with somebody shouting "Fire". A single protein is a very degenerate case of the conversation. There will be a few markers like that, that are simple markers, but mostly I think we'll look at things that are much more complex patterns that happen in multiple proteins. Dosage is another reason why pharma companies will get very interested in proteomics, and it probably will make a big difference in research. Right now you can't tell what's happening until it gets all the way up to having a symptom in a patient. If you have something that takes a long time to play out, like Alzheimer's disease, or ALS, you really don't know if your drug is doing any good for years and years. You have no idea if the dosage is too high, or the dosage is correct. The feedback loop is very, very indirect, and lots of other things are affecting it, too. But if you could actually look at the proteins and notice this bad problem of communication between the cells, that's causing plaque formation in the brain in the case of Alzheimer's, then you might be able to see the response of the drug immediately, even though the symptoms aren't changing yet. The symptoms may take years to change, but you can see the drug is effective in this patient immediately… or that it is not, so you can move on to trying the next drug. You could titrate the dose and very quickly say. You can titrate the dose not only so the guessing holds the correct, safe dose, but actually specifically for the patient. We know that people respond very differently to drugs. Right now it's a trial and error process. They give you a little bit, if that doesn't work they give you more. We see this happening even with simple drugs like blood pressure drugs. Now, with blood pressure, doctors can measure blood pressure easily. They should give you a small dose of the drug first, they see if your blood pressure went down enough, and they can give you a little bit bigger dose. You can do that as a quick loop and you calibrate the response for an individual because you can measure blood pressure. Well, you can't do that for something where the outcome is years away. Proteomics ought to let us do that, too. On the way proteomics will change treatment Something that I skipped over in describing the new treatment paradigm, and the simulation paradigm of treating rather than the diagnosis paradigm, is that right now what you do is you diagnose, and you select a course of treatment. Now, what really happens if it doesn't work, maybe you switch and jump on to a different track. But the interesting thing, once you can kind of measure the dynamic state variables, is you're constantly redoing that. You replan every time you go into the doctor. There is not a notion of staying the course, there's no reason to stay the course because you can tell you're getting closer. You redesign a new treatment every time you remeasure. You're constantly getting feedback. You don't just design a special customized treatment per person, you do it per person per time, per person per visit to the doctor. What you're trying to do is guide it back to a healthy state, basically. But the other great thing is because you're looking at the whole state, you're not just treating one thing at once. That's the other thing that's a flaw in this idea we've gotten about medicine, which is in the infectious disease model. The fact that you have malaria is the main event. You've got to kill off that malaria before anything else can happen. But in the systems diseases, there's lots going on in the body, constantly. So when we say a treatment is safe and effective, the way that we test that is we're testing one thing at once, not looking at everything else. So we say, "Okay, well, some statins lower your cholesterol, which we think is a surrogate for you're going to have a heart attack", so we give everybody a statin. Now, if you look at some of the early monkey studies where they first studied statins, and proved that it lowered cholesterol, the monkeys that were taking the statin had a higher death rate than the monkeys that weren't taking it. What does that mean? Well, they kind of ignored it, because they looked at the deaths and they were from accidents, or getting into fights, things like that. I bet that it's going to turn out that statins actually cause you to get into fights, and have accidents. It will have effects on your mind that weren't studied in all the studies of statins, and in fact, statins may not be good for you. Or they may be good for you for reasons that have nothing to do with lowering cholesterol. That's another thing that we're discovering in statins. The idea that we go in there, and we have this very complicated system, and pick one variable and say, "Does this one variable get better when we give this person this pill?", and then say, "Okay, well, it did." The engine rate went up because we poured this goop into the engine. But is that really good? Well, maybe the speed went up because it broke the regulator or because it clogged up the safety valve. So right now when we test the drug, we're looking at one thing at once. We only discover these bad side effects in these retrospective studies looking back after people have been taking the drug for a long time. What most of these drugs do is shift the balance. They're trade-offs. There is a reason why you don't naturally produce statins. I don't think it's because nature didn't think of the idea, it's probably because statins have some pluses and minuses, and so what you're doing is you're rebalancing things, tipping things in a certain direction. The reason that's relevant is if you're in the paradigm of diagnose the disease, treat the disease, then that tends toward treating the disease at the cost of making everything else a little worse, than if you're looking at the whole system, and trying to optimize the whole system. Proteomics is looking much more at the whole system. Proteomics can also tell you things that can give some substance to what nutritionists have been talking about. If you look at traditional Chinese medicine, or Ayurvedic medicine and things like that, it's all in terms of balances, restoring this force against that force, but it doesn't have a very good model. It is a highly oversimplified model that's been made up without much scientific information going on, just a lot of time going into it. If you had a much better model, then you could probably rationally understand what foods you should really eat that bring your body back into balance. It is probably very different for different people, and so I don't think the treatment is necessarily going to be taking a pill. You will take pills, but you'll also change diets, or you may discover that it's very important for you not to be stressed out in the afternoon, you may find it's important for you to get lots of oxygen, or do something very aerobic. You may find out that you better not get cold. Or we may deliberately heat you up to an abnormal amount for a little while. Maybe you will need sequences of these things. I don't think treatments will be "a thing", like a pill, I think treatments will be perturbations, bringing you toward health, with some feedback as to what results all those perturbations are having. In a sense we already have home proteomic tests. Some of these home pregnancy tests may be that. What's happened is, for various reasons, we have luckily discovered certain proteins that are diagnostic, PSA is a great example. PSA is a protein, a prostate-specific antigen, and for various reasons we happened to notice that this was a marker for prostate cancer, that it was associated with prostate cancer. Now when you go get a blood test, if you're male you probably automatically get a PSA test. That is a protein test — a test for a specific protein. Once you can look at the whole protein, one of the things that will happen early is you'll identify specific proteins to test for, and those may be home tests. They may be finger prick tests, or there may even be indicators of a protein that are excreted in your urine, so it wouldn't surprise me at all if you get home tests that come out that were identified by looking at the whole proteome. But my guess is, again, those are going to be kind of unusual, special cases. In some sense it's really lucky that there happens to be a single protein that's associated with inflammation in the prostate. In fact, maybe it's lucky, maybe it's not, because there are a lot of people getting needles stuck in them unnecessarily because of this test, and probably they would be much happier not being told they have prostate cancer, because it probably won't hurt them anyway. Maybe the needles are worse than what would have happened without the test. It causes a lot of worry, and stress, and maybe the stress even makes them prone to some other kind of cancer. Probably there is a much more sophisticated combination of lots of different proteins that you can look at and say, "This is an inflammation of the prostate that's actually not cancer." Or, "This is an inflammation that looks like this particular kind of cancer that responds to this drug, while this is a particular kind of cancer that grows very slowly, and it's not going to kill you. You'll die of something else first, so you don't need to worry about it." Once we get much more subtle measures, once we can listen to that conversation and find out what's actually going on, then I think there will be a lot less treatment. We do a lot of overtreating of things, and a lot of damage by treatments. That's actually one of the only things that can actually reduce the cost of medical care. The cost of medical care is mostly way down the line when people at hospitals, are already pretty damaged by disease and treatment by the time they become very expensive. If what you can do is spend more of the money up front diagnosing things, tweaking things before it gets to that stage, then that is a win-win because it's better for the patient to get less treatment, and better for the insurance company because you never get to the hospital. Of course, the doctors actually are happy because they really do want to cure the patient. They have more tools to actually know what's going on. It's very frustrating for the doctors to know that a treatment might not work. Doctors hate this thing of giving you a sequence of poisons: hopefully we'll kill the cancer faster than it will kill you. That's a horrible thing to do to a patient. I think oncologists would love to have better ideas of what the effects of the treatments that they're giving are, and is it actually doing any good. They want to avoid giving people treatments that are not going to help, that are going to make them sick. On home testing I'm sure we'll have examples where people can do self-testing, perhaps for a single protein. I think it's going to be rare cases. Sometime we may see proteins or parts of them in the urine. Mostly proteins get broken down, unless you have something like bladder cancer. Usually we test the blood. But, diabetics do blood draws all the time at home, and tests. So I can certainly imagine things that are the equivalent of diabetic sugar meters, glucose meters that you're adjusting your own dose of blood pressure medication, or anti-cancer medication, or something like that. Right now proteomics makes it very expensive to do because we're just able to do it for the first time. But certainly once you've identified what you're looking for, then there is some fairly standard methods of changing that, and turning that into tests that are very easy. The classical method is you develop an antibody to the protein, and then you can make something that changes color. More and more it will be changes to the conductivity of a transistor so that you won't read out a color, you'll have a little machine that does the analysis, not just indicating presence or absence. I think the interesting information will be in the levels of many different proteins. The picture I showed you was a protein that was produced in one and not in the other. Much more common, though, we see proteins that change in levels by 20 percent or something like that. A lot of the information isn't just on/off, it's in the concentration. You don't totally turn it on or off, you change the rate at which you're producing it and a lot of drugs basically do that, or they change the rate of production or destruction of something. They upregulate something, downregulate something else. If you take BRCA as an example, there's another protein that I think regulates a promoter of BRCA production, and actually if you have a mutation in that, too, then the mutation in BRCA is less important because it's not regulated. That's a completely different kind of subcategory of breast cancer. When you try to downregulate something, it is because you have too much of it, so you lower it by giving a drug that suppresses its production or speeds up its destruction It's all in the quantities, it's not just present or absent like it is in the genome, and that's the thing that's really neat about the genome is it really is digital. You either have a gene, or you don't. You have this variant of the gene or you don't. You have one or two copies of it. I'm emphasizing blood because it's nice you have a collecting system built into your body that goes around and touches every place in your body and collects fluids. It's very convenient for diagnostics. But there will probably be things that happen in tears, or in saliva, or in lymphatic fluid, or spinal fluid, but your body is plumbed very nicely for blood so that you can get it out easily, and since it delivers nutrients, and gets rid of waste, it pretty much is involved in anything very dramatic that's happening in the body. It's good low-hanging fruit, at least. In diabetes treatment, what we do now is we basically get around your pancreas. Doing what your pancreas does by adding insulin. We try to mimic the pancreas. Proteomics may allow us to actually stop the processes that cause your pancreas to go bad earlier. We know that that's something that can be affected by diet. Again, it's probably predispositions, so if you're missing certain vocabulary words, it's harder for certain kinds of processes to work, and so you are particularly susceptible to certain kinds of problems, so that's where genetics comes out. Then proteomics can see, are you actually having those problems that you're susceptible to, or are your other redundant mechanisms taking up the slack for it? The body seems to be highly redundant, and often has lots of mechanisms for doing anything important. On redundancy and treatment Probably the biggest surprise that happened with genetics is once we had the ability to knock out genes, everyone thought, "This will be great, we'll knock out the gene and see what breaks." Well, it turns out mostly when you knock out a gene, at least half the time nothing seems to break. There was some redundant thing that just took up the slack. Probably if you did very careful studies on those knock-out mice you would find out that they were more susceptible to certain kinds of diseases or breakdowns because they're missing one of their redundant mechanisms. It's interesting that evolved systems, much more than engineered systems, are evolved to be robust and redundant, and if you think about it, robustness is a kind of information hiding. What you wanted to do is you wanted to respond the same under many different kinds of circumstances, and with some of its parts broken. What you're doing is you're hiding the information in effect about, how it's working. The very process of making something robust is a process of hiding the information at the level of the symptoms, at the level the physician is looking at. In a very real sense, evolution has evolved your body to make the systems uninformative about what's going on inside. It's kind of amazing that a doctor can look at things on the outside of you, and take your temperature, that it works at all that you can look at the outside of somebody and decide what you should do to them to make them better because evolution has evolved it for that not to work, in effect. It's actively hiding the symptoms of what it's doing, because that's what it's evolved to do, it's evolved to do the same thing no matter whether it's working or not in some sense, or whether each piece of it is working or not. You do need to get to a different level to see what's going wrong. Mostly the body fixes itself when it's cancering, and so if you can just sort of help it, tilt it in the right direction, probably most cancers would fix themselves if you give them a chance to. Oddly, though, if you think about that and think about chemotherapy, which is basically the strategy of let's try to poison the cancer, even though we poison you, it seem crazy. Let's try to have a poison that's just enough not to kill you, but to kill the cancer. Well, you're also probably compromising all those mechanisms that fight the cancer, rather than propping them up. In some sense we're probably making the body's job harder in our attempts to treat it. Mainstream medicine tries to understand what are the mechanisms, what are the pathways, tries to design things that enhance, or block something bad from happening and so on. Proteomics is a new tool that gives you a whole lot more information to do that with, and once you have a whole lot more information, then that lets you do a much more informed dynamic intervention. It helps to give you insight in the actual works of the pathways. That's a very mainstream idea. I don't think anybody would argue with that. On symbiosis A really interesting point is that probably a lot of the system that is our healthy body actually doesn't have human DNA at all. It has some other microbial DNA, and we probably are a complicated ecosystem of different types of our own cells, and lots of non-human microbial cells. Once we start looking at the proteome, we'll be looking actually at the conversation of all of those cells, not just the human cells. Some of those stripes that show up in the picture I showed, we can say, "Oh, that corresponds to this human gene." Some of them, we don't know they might be produced by some combination of other proteins, might be some other organism's protein. Microbial protein would show up in that too, or response to microbes. One of the beauties of this is that we see everything, whether it's of human origin or not. We actually can see it all in the proteome. On the National Cancer Institute The leaders of the National Cancer Institute are very keenly aware of how little progress has actually been made in the treatment of cancer. This is something they pay a lot of attention to. They're thinking very laterally in giving funding to people like me to work on cancer. What they've done is to say 'Let's bring in some new kind of thinking to this, and let's have a program where we have physical scientists be the principle investigators, partnered with the co-investigators who are clinicians and biological scientists. I'm partnering with David Agus, for example. But giving money to the physical scientist is a pretty radical idea; you can imagine it is very controversial within the biological community. NCI has started start a few of these centers, and given them five years to work. They need to be interdisciplinary and geographically distributed. Our center at USC has people all over the United States involved in it, like Cold Spring Harbor, Stanford, Arizona, UT, NYU and Caltech. Typically these labs will have a particular technique for studying biology. It might be measuring proteins within a single cell, or imaging the growth of a tumor. Very often these things are very, very hard to do, and so people have built their career on a new way of sensing proteins inside the cells, and they have teams of graduate students who are refining this technique, and doing variations of this technique, and developing it and so on. There is about a dozen of these physical sciences centers, each of them is the same kind of structure, there is a physical scientist who is paired with an oncologist, and a group of people that are geographically distributed, applying their techniques to a program of research. In our particular program of research, as I've described, we're trying to take one cancer, study it with all these different techniques, and build a model of how it develops. Different centers have different goals for what they do, but what they all have in common is somebody who is not a biologist trying to use the tools of biology to study cancer in some way. The proposals for these centers got reviewed by a peer review process, with biologists evaluating at them. One of the reasons that the biologists liked our program was that, surprisingly enough, it's really unusual, even unique for somebody to take one line of cancer and study the same line of cancer with all of these different tools. Typically what people do is study a different cancer with a different tool, and they find the cancer, the type of cells that they can grow in that lab that works well with their tool. The idea of picking a few different specific cell lines, and studying them from a lot of different dimensions, and lots of different scales; I believe that, our proposal probably got funded because the biologists said, "That's going to be useful even though we don't believe this modeling stuff will ever work. Just doing that will be very useful." A lot of the resources that have been put into cancer have generated the preconditions so that we can do this. I don't feel those resources were wasted in any way. We really understand a huge amount about pathways, and specific mechanisms, so we know a whole lot more about cancer, even though we can't treat it much better in many cases. We have a lot more information, and that information can be made more useful now that we have this proteomic information. This isn't in the category of throw away everything we've done and start over, this is an incremental progress next step that's built on top of an incredible mountain of work. On how these efforts could fail There are a couple of ways that I could be wrong, or fail. The timing could be wrong. It could be that we don't have enough of that information built up about the mechanism to interpret these results yet, so it could be that when we really started analyzing we just failed to find the patterns of proteins that correlate with useful things to treat. I would bet then that that's probably just an issue of timing. We're too early, we don't have the right information to bring together with it, or maybe we're not doing the measurement in enough detail. Maybe it's not these 20 percent changes, maybe it's 2 percent changes, or maybe it's changes in much rarer proteins that we're not measuring by this method, something like that. Maybe it's not in the blood. Maybe most of the information stayed inside the cell. Maybe the action is happening within the cell, not between cells, in which case, probably it will be much longer before it's diagnostically useful in medicine. Eventually, almost certainly, it will be right. Whether, the timing is right to actually apply this information to medicine in the near future is a risky proposition, and the answer is probably they'll be partially right. There will be some things you can apply it to, and some things that remain mysteries until you look at much more detail of what's going on within each cell, or something like that. Certainly there are other kinds of molecules that are important, too. It's not just proteins. We know, for example, glucose is important. There are small molecules that are important. Now, most of the small molecules, their production, breakdown, are regulated by proteins, so I'm guessing that if you have all the proteins' state, then you can infer what's going on with the other stuff. But there is state in the body in other things besides proteins. But most of the information seems to be in the proteins. The body has lots of mechanisms for not only transmitting these proteins, but listening to them. If you look at what these molecular machines do, they talk to each other through these proteins; they say, "If you turn on, produce more of that, or less of that". They're measuring these proteins all the time, and responding to them. That's how your body works, that's how the feedback loops work. Your body is doing proteomics constantly. It's exciting because for the first time we're really looking at the variables of this complex process, the dynamic variables, which is what life is. That may be too complex for us to comprehend, but at least we're listening in on the conversation. Whether we can understand it or not, we'll start learning in the next few years.