Jennifer Doudna: Well, that question, to me, really brings up a couple of different but important points.  One is that something like depression is not the result of a single gene or even a handful of genes.  It’s almost certainly the result of hundreds or thousands of genes, as well as the environment that a person has experienced.  So it’s going to be very complicated to try to — even if we wanted to — to fix it with genome editing, at least the way the technology is right now. And the other thing is  — the other point about your question that’s so interesting — is that it sort of gets to this question of what makes us human. What makes us unique as individuals?  What do we value about the diversity of our life here on Earth?  I think that, for many people, the diversity of life is one of the things that makes it so rich and so wonderful.  So we wouldn’t want to have a way to make us all the same.