Craig Thompson didn't set out to be a spokesman for the importance of bioenergetics in determining cell fate. Now a professor of medicine and chair of cancer biology at the University of Pennsylvania School of Medicine, he trained as a physician and became interested in research when he realized that "we really didn't understand quite as much as we needed to about basic biology to develop effective therapies for patients," he says. To pay for medical school, Thompson accepted a scholarship from the Navy and, following his training, he turned his attention to medical procedures that were of interest to the military – for example, bone marrow transplantation. The Navy planned to be prepared should such treatments become necessary to combat radiation injury on US soil.