In today’s New York Times, I have a feature about the X chromosome. The X chromosome is one of those things that we learn about early on in school, and yet it still contains mysteries–ones that potentially have a direct impact on our health. Men have one X chromosome and one Y, while women have two X’s. This imbalance has led to all sorts of remarkable things–most remarkable of which is the fact that women shut down one of their X chromosomes–but which chromosome (mom or dad’s) depends on the cell.

I explore several lines of research in this piece, but the original nudge came from one new study in particular. Jeremy Nathans of Johns Hopkins and his colleagues