Genetic IQ tests. DNA detective work. Virtual drug trials. These were some of the surprising new uses of DNA information that emerged over the last 12 months as genetic studies became larger than ever before.

Think back to 2003. We had just decoded the first human genome, and scientists still spent their time searching for very specific gene errors that cause quite serious inherited problems, like muscular dystrophy. Now, though, we’re dealing with information on millions of genomes. And the gene hunts are not only bigger—they’re fundamentally different. They’re starting to unearth the genetic roots of common illnesses and personality traits, and they’re making genetic privacy all but impossible.

Here are the trends you need to know, from MIT Technology Review’s own coverage over the last year.

Consumers: It’s all about genetic data. Now it’s being collected on millions of people, in national efforts and commercial ones too.

Last February, we reported that 12 million people had already taken consumer DNA tests. Since that figure has been reliably doubling every year, it’s probably up to 25 million by now. In fact, DNA reports are now a mass-appeal item. During the Thanksgiving weekend, the gene test from AncestryDNA, which tells people where their ancestors are from, was among the top-selling items.

Big data: To understand the genome, scientists say, they need to study as many people as they can, all at once. In 2018, several gene hunts broke the million-person mark for the first time. These included searches for the genetic bases of insomnia and educational success. To do it, researchers tapped national biobanks and also got help from 23andMe, the popular gene test company, whose users can sign up to participate in research.

Polygenic scores: Some diseases are due to a single gene that goes wrong. But big killers like heart disease aren’t like that—instead, they’re influenced by hundreds of genetic factors. That’s why a new way of predicting risks from a person’s entire genome was the most important story of the year (see polygenic scores on our 10 Breakthrough Technologies list). The new scores can handicap a person’s odds of breast cancer, of getting through college, or even of being tall enough for the NBA. In 2019, keep an eye on gene-test companies like 23andMe and Color Genomics to see if they launch such gene predictions commercially.

Genetic IQ tests: Genes don’t affect just what we look like, but who we are. Now some scientists say these same DNA scores can offer a decent guess at how smart a kid will be later in life. The unanswered question: how we should use this information, if at all?

Testing embryos: Yes, it’s probably going to be exactly like that sci-fi movie Gattaca, the one about a world where parents pick their kids from a petri dish. Already, IVF centers run gene tests and let parents pick embryos to avoid certain serious disease risks. Now Genomic Prediction, a New Jersey company we exclusively covered in 2017, says it’s ready to begin testing embryos to grade their future educational potential. So forget CRISPR babies—designer kids are already here.

Racial bias: Here’s something that’s not so great: about 80% of the DNA ever analyzed is from white people of European ancestry. It means some new discoveries and commercial tests only work in white people and don’t apply to Africans, Asians, Latinos, or others ancestry groups whose genetic patterns differ. There are good scientific reasons to expand the gene hunt, says Stanford University geneticist Carlos D. Bustamante. We may be missing health breakthroughs by looking too narrowly.

Mimicking clinical trials: Did you know you’re part of a gigantic, random experiment? It’s true. Or at least some geneticists see you that way. And now they’ve come up with a very clever trick called Mendelian randomization that uses people’s medical information to predict which new drugs will work for them and which won’t.

Crime fighters: The more DNA data is out there, the easier it is to find out who a drop of blood or a hair follicle belongs to. That’s what the Golden State Killer learned in April, when he was caught by sleuths employing an informal collection of DNA profiles and genealogical trees. In fact, the way the math works out, genetic anonymity is kaput—sine pretty much all of us have a relative in a DNA database already. One genetic genealogist, CeCe Moore, told us that she’s identified 27 murderers and rapists since April. A very good year.