Doug Sawyer is a cardiologist and cell biologist whose research focuses on how the adult heart maintains and repairs itself. An area of particular interest is how neuregulin, and the erbB2 and erbB4 receptors function in the adult heart to regulate response to injury. In animal and tissue culture models, his laboratory has used a variety of approaches to demonstrate the role of neuregulin as a growth and survival factor involved in cardiac homeostasis. This work has contributed to the development of neuregulin-1 as a possible therapeutic in heart disease. His laboratory has also identified exercise as a physiological regulator of neuregulin biology in rodents, and is currently carrying out clinical studies aimed at understanding the implications of this finding for the cardiac effects of exercise. In complementary work, his laboratory has examined molecular mechanisms by which cancer therapies targeting erbB2 interact to augment cardiac injury by anthracyclines. His laboratory has made several fundamental observations demonstrating novel mechanisms of injury from anthracycline exposure, and shown that neuregulin/erbB signaling suppresses this cellular injury. He is now carrying out clinical studies examining whether these observations can be translated into strategies to predict which individuals being treated with these agents are most likely to get cardiovascular complications.