At-home DNA test kits are so ubiquitous that it’s easy to forget how insane the technology is. For around $100, you get a peek inside your genome—something that once required a roomful of PhDs and a supercomputer. But don’t be fooled: The big push to increase the numbers of customers isn’t entirely about revealing your ancestry, even whether you’re a descendant of Abraham Lincoln. It’s a way to get your DNA‚ then sell it to companies making everything from pharmaceuticals to face lotion. So here are a few things to know that even the fine print may not tell you.

1. Drug companies pay top dollar for your DNA.

When you OK the DNA kit terms and conditions, you’re offered the choice to allow your DNA info to be used for scientific studies. Additionally, the lab holds on to the swab and may have the ability to reanalyze it.

“The genetic information is sold to researchers who use the data to develop drugs, treatments, and products,” says Bob Gellman, an expert in privacy, freedom of information, and health confidentiality and a former House of Representatives staffer. “That’s where the money is.” For instance, in 2018, U.K.-based pharmaceutical company GlaxoSmithKline announced a four-year, $300 million investment in 23andMe. This may help explain why the kits are so affordable. The bigger the participant pool, the more valuable the data.

There’s nothing inherently wrong with this. Kit company 23andMe spokesperson Liza Crenshaw explained that partnering companies aren’t simply given a pile of raw data to play with. Instead, they’re sent an aggregate. So: A certain percentage of men aged 30 to 35 express a particular gene. This leads to participant privacy.

Individuals’ names aren’t attached to the info, and the companies follow the same informed consent practices that all research institutions do. It also means that your spit can be used to help people; pharmaceutical and other research companies analyze sets of genetic data to help predict disease patterns and make more effective treatments.

2. It could also be used to choose potato chip flavors.

Consumer product companies are also keen to buy genetic information in bulk, Gellman says. They can do analyses that look for genetic taste markers which influence, for example, how much sour flavoring to use in a batch of gummies, or how much heat they can add to salsa to satisfy the most people. It’s even more valuable if there’s a questionnaire that goes out to participants. For example, if a brewery wants to make a new stout, they may want to find out the results of five genetic markers that predict a fondness for dark beers, and then couple that with a set of questions that asks people about their taste in suds. It’s basically one of the best focus groups of all time.

Some partner companies may use the genetics component as a marketing tool. In 2017, Procter & Gamble, the consumer goods behemoth, announced findings about skin aging using 23andMe data; it was in conjunction with the release of new Olay products.

3. After you do the kit, get ready for the upsell.

Other businesses use your genetic intel to sell you stuff, and they are flourishing. The company Rootine uses DNA tests and a questionnaire to create a custom vitamin regimen. DNA kit company Helix partners with several consumer outfits, including Vinome, which recommends wine based on the taste preferences revealed in your genes, and Dot One, which will knit you a tartan blanket, scarf, socks, and more based on the unique artistic pattern of your DNA strands.

4. Your DNA is another form of medical information.

Your genome says a lot about you, like whether you have a genetic predisposition to certain diseases (mental illness, cancer, cardiac issues—the list goes on). But the kits aren’t subject to HIPAA, the medical-privacy regulations that protect your medical information. And it’s not easy to scrub the world of your DNA information once it’s out there, Gellman says.

And for people buying insurance on the open market, if laws don’t keep up with advancements in genetic testing, there could come a day when DNA info influences the way health insurance companies offer coverage to individuals. For instance, the data could reveal a marker that is associated with an increased risk for Alzheimer’s—a costly disease in the long term. So perhaps an insurance provider would charge that individual more. And it could change the way life insurance companies make policy decisions (the same way they upcharge for smokers).

Gelman also warns that potential employers might use the data to discriminate against job candidates. Congress isn’t necessarily helping. In fact, Republican lawmakers in the House introduced a bill which would have required that certain employees who participate in workplace wellness programs give their DNA test results to their employer or risk getting charged more for health insurance.

5. Hackers may want it.

DNA reveals potentially damaging information, and it has become a target for cybercrime. Hackers who gain access may offer to ransom it back to the owner, at the risk of exposing sensitive information, like medical issues or family secrets. Some breach attempts have been successful. In 2018, a group of cybercriminals, probably from Eastern Europe, targeted Indiana-based Hancock Health hospitals and got paid four Bitcoin—at the time worth about $50,000—not to disperse patient information. And in December 2018, the British government announced that its 100,000 Genomes Project was the target of a string of unsuccessful cyberattacks from “foreign actors” seeking to steal the complete, sequenced genomes of 85,000 participants.

Last year, hackers targeted the DNA test kit company MyHeritage; they got only as far as accessing 92 million email addresses. DNA kit makers spend big money on database security. A massive breach would be extremely costly, both in dollars and in consumer trust. (Case in point: the Equifax credit data breach.) But given the high value of DNA, cybercriminals will keep trying.

RESEARCHERS USE THE DATA TO DEVELOP DRUGS, TREATMENTS, AND PRODUCTS. THAT’S WHERE THE MONEY IS.

6. If you’ve already gotten analyzed, you can still opt out.

Even if people opted into participating in research when they originally signed up, it’s not too late to change their minds. Each kit company has its own procedure, so search in the website’s privacy tab to understand the steps. You may need to contact the lab holding the sample and ask them to destroy it. But that doesn’t mean the lab will destroy your sample; some federal regulation may require the labs to hold on to them for several years.

7. You can sell it.

This year, a number of DNA data marketplaces are set to launch, allowing individuals to upload their genetic information, which companies—particularly pharmaceutical and research institutions—can buy, says Alex Gorbachev, cofounder of one such marketplace called Zenome, based in Moscow. How much a person can net is to be determined.

Zenome estimates payouts from $1,000 to $2,000 a year. Dawn Barry, co-founder of U.S.-based exchange LunaDNA, says, “It’s tough to estimate, since it will depend on the number of participants, but users may be looking at payouts of around $21 each time their DNA is accessed.” To earn more, participants will be asked to complete questionnaires about their tastes and preferences, which helps refine the info gleaned from DNA. Before you sign up, be sure to understand who “owns” your data—you or them—as it differs among companies.

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