 A crucial question is whether or not this gene-editing treatment is lasting. We edit the cells today. Will the edited cells be around to keep you healthy years from now, potentially? So to test that, we edited human cells in the laboratory. We then injected them into mice. And then we looked at the editing of the cells four months later and asked whether or not the edited cells hung around. When we do that, we find that about 2% of the stem cells that remain in the bone marrow after four months are edited, which, in the case of sickle cell disease, is that level of editing is likely to have clinical benefit. But we would like to get a little bit better than 2% in the future. As for the excitement about the future of this technique, I'm extremely excited because we haven't been trying this for very long. We will get better. And what we have right now is already, if we can scale it up and make sure that it works well, is already good enough to form the basis of a clinical trial to cure sickle cell disease with gene editing.