When you're doing kidney transplants, you have to find out who can exchange kidneys with whom, doing blood tests to make sure it's true. You can't just work on the preliminary data. Then you have to organize the logistics.
I moved to Harvard in 1998, and in 2000 the first kidney exchange in the United States was done at a hospital nearby. I started to think, 'Gee, there might be a way where I could help organize it, make it easier for people to find kidneys.'