 I have thought a lot about the way that CRISPR technology might be used and I mostly feel excited because I think that it's a very exciting technology that's going to do a lot of good in human society and for human health. I do think that there are reasons to be cautious in the way we implement it for various things, in particular for doing clinical applications in embryos like human embryos. If you do the editing in adult tissues, those are changes that are made in an individual, but they're not passed on to children. I think most people would feel that genome editing in adults is, or at least might be, for some applications a very appropriate technology. It might be analogous to taking a pill or any other kind of therapeutic drug that you might use in a patient for treating cancer or some other disease. And if you could do something profound like eliminate sickle cell anemia or eliminate cystic fibrosis or have someone not have to suffer from Huntington's disease anymore or worry about getting it when they get older. What certainly raises ethical implications is whether that sort of change should be made in eggs or sperm or embryos where those changes could then be passed on to the next generation. So I feel that it's appropriate with guidelines to conduct research in those kinds of systems, even in human embryos. I don't think that it would be appropriate to use this technology, at least today, for any kind of clinical application in human embryos. The science is going a thousand miles an hour. One of the roles that we as scientists need to play is to really communicate the power of this technology and how we can be responsible in using it. For that conversation to carry weight globally, it really needs to be a conversation that involves scientists that are international. Do we know enough about the human genome to understand the impact of making changes to it in a developing embryo? And so I think that there I would like to see our society draw a line and say that we won't go there right now. We'll take the time that we need to really think about this.