William C. Knowler is chief of the Diabetes Epidemiology and Clinical Research Section in the Division of Intramural Research at the National Institute of Diabetes and Digestive and Kidney Diseases. The Institute has primary responsibility for diabetes research at the National Institutes of Health. For more than three decades, Dr. Knowler has conducted research on diabetes in the Gila River Indian Community in Arizona, looking for insights into the genetic and environmental factors that lead to the development of Type 2 diabetes. His focus is risk factors for Type 2 diabetes and its complications, the relationship between obesity and diabetes and diagnostic criteria for diabetes. Dr. Knowler has a bachelor's degree from the University of Iowa, a medical degree from Harvard, and a master's degree and doctorate in public health from Harvard.