Browse the published research from 23andMe, and you may be amazed by how much the genetic testing startup has discovered in a few years.

Send in your spit and take a few surveys, and you'll get an idea of how much more is coming.

Since launching in 2006, 23andMe has collected and analyzed DNA samples from 1.2-million customers, with the majority allowing their data to be used in research. Although facing controversy over (past) FDA concerns, (current) partnerships with pharmaceutical companies, and (future) plans to develop its own drugs, the billion-dollar company has always said its mission is to help people access, understand, and benefit from the human genome. There’s no doubt it has made contributions there.

One of 23andMe’s biggest discoveries came this summer with a paper linking 17 genetic tweaks, or SNPs (pronounced "snips"), that appear to be tied to one's risk of developing Major Depressive Disorder (MDD). Past attempts to identify genetic connections with depression were extremely limited, largely because other researchers didn’t have enough data.

"Everyone is recognizing that this is a numbers problem," Ashley Winslow, director of neurogenetics at the University of Pennsylvania, told MIT Tech Review. "It’s hard if not impossible to get to the numbers that we saw in the 23andMe study."

"My group has been chasing depression genes for more than a decade without success, so as you can imagine we were really thrilled with the outcome," Harvard psychiatry professor Roy Perlis, one of the leading authors of the paper and the Associate Director of the Psychiatric Genetics Program at Massachusetts General Hospital, told Business Insider.

Studies like this could help pave the way to better understanding and treatment of diseases. In fact, 23andMe was also involved this summer in a study focused on the treatment of depression, which linked one gene variant to lower efficacy in one drug.

23andMe is, of course, far from the only group doing research in this field: thousands of genome-wide association studies have been published in recent years. Where the company stands out is in its extensive use of surveys as an easy yet effective way to get data.

23andMe has "proven that volunteer-reporter phenotypes give much the same results as information collected in more traditional ways," Teri Manolio, Director of Genomic Medicine at the National Human Genome Research Institute, wrote in an email.

How much the company has contributed beyond that is a matter of opinion.

Manolio said the company has not played a large role so far, though she also said it had probably done more than other personal genomics companies and that it might play a larger role in the future.

Peter Visscher, chair of Quantitative Genomics at the University of Queensland, was more positive. "23andMe has been an important player in research involving genome-wide association studies (GWAS)," he wrote in an email. "23andMe has contributed significantly to discoveries of new genes across a range of traits and diseases, including, for example, educational attainment and Parkinson’s Disease."

He also noted that the company could be a lot more helpful by sharing additional data with researchers.

23andMe has so far discovered hundreds of genetic links to traits, including parts of DNA that relate to freckling, sneezing, hair loss, not liking the taste of cilantro, smelling asparagus in your pee, allergies, asthma, motion sickness, emotional response, age of puberty, bone density, myopia, hypothyroidism, problem drinking, sleep habits, neuroticism, Parkinson’s, cancer, and more.

The company has also helped establish links between DNA and education attainment, show a wider risk of neurodegenerative diseases, introduce new tech for analyzing Parkinson’s and neurodegenerative diseases, and more.

Then there’s the stuff that’s yet to come. 23andMe members are invited to click through hundreds of questions, asking them about everything from narcissism to math skills, nail biting to vocabulary. Many of these traits haven't been tied to genetics yet but could be some day.

23andMe currently provides a lot of genetic information for $199 to customers who send in a tube of spit. Some of that info is just interesting, like how much Neanderthal DNA people carry, where their more recent ancestors came from, and how likely they are to have dark hair, freckles, and a preference for salty snacks. Some of it is medically important, like whether they carry potentially dangerous variants for things like cystic fibrosis and sickle cell anemia.

Director of Clinical Development at 23andme, Erynn Gordon, told us the company is continually adding more traits to client reports, as well as publishing research. Take misophonia, the genetically linked characteristic of getting annoyed by hearing other people chewing.

"I don’t think it’s out yet, but that might be something that you would see in the future," Gordon said.

The ability to sing in tune or clap in rhythm? Attractiveness to mosquitos? Difficulty hearing conversations in loud areas? These are all things that 23andMe asks about, meaning they are things the company can begin to analyze, figuring out where genetics matter and how.

"We’re just scratching the surface of our understanding," founder Anne Wojcicki said earlier this year.

What will the company do with all its new info? Good, we hope.