The China study is particularly compelling for a couple reasons. First, when you find a variant that’s associated with reduced drinking, you have to wonder what else that variant might do to change your risk. So the people with the variant might drink less, but they also might have something going on metabolically that would reduce risk. Luckily, in the areas of China the study dealt with, the fact that women drink very little, no matter their genes, offered a kind of control group. In women, the variant made no difference to disease risk, which gives us a pretty good idea that, in men, it was the drinking.