Dr. William G. Kaelin Jr.

William G. Kaelin Jr., MD, is an American physician-scientist recognized for his research into the molecular mechanisms of oxygen sensing and its impact on cancer biology. Kaelin holds the title of Sidney Farber Professor of Medicine in the Department of Medicine at Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, and has served as a Howard Hughes Medical Institute investigator. He earned his undergraduate and MD degrees from Duke University and completed his internal medicine training at Johns Hopkins Hospital, where he served as chief medical resident. Kaelin was a medical oncology clinical fellow at Dana-Farber and a postdoctoral fellow in the laboratory of David Livingston, where he began his studies of tumor suppressor proteins before becoming an independent investigator at Dana-Farber.

Kaelin's research has focused on the gene underlying von Hippel-Lindau (VHL) syndrome, a rare familial cancer caused by mutations in the VHL gene. Individuals with VHL develop tumors in various organs, including the central nervous system, kidneys, and pancreas. Kaelin observed that tumor growth in VHL was often associated with increased blood vessel formation, which he linked to changes in oxygen availability. His work revealed that VHL regulates levels of hypoxia-inducible factor (HIF), a protein that modulates cellular response to low oxygen, triggering angiogenesis and supporting tumor growth. Kaelin's discovery of a molecular switch that makes HIF oxygen-sensitive advanced the understanding of how cells respond to oxygen variations, informing the development of targeted anticancer therapies.

Kaelin's findings demonstrated that persistent HIF activity enables tumor cells to grow in low-oxygen environments, contributing to the development of drugs that block HIF activity, particularly for kidney cancer. He was awarded the Nobel Prize in Physiology or Medicine, alongside Peter J. Ratcliffe and Gregg L. Semenza, for work on cellular adaptation to oxygen availability. Kaelin and his collaborators elucidated the molecular events that allow multicellular animals to adjust their physiology to varying oxygen levels, with implications for new therapeutics in cancer, cardiovascular disease, anemia, and macular degeneration. His research at Dana-Farber has focused on the role of mutations in tumor suppressor genes, including retinoblastoma, von Hippel-Lindau, and p53, in cancer development.

Kaelin's honors include the Massry Prize, the Lasker Award for medical science, the Grand Prix of the Fondation Lefoulon-Delalande from the Institute of France, the Canada Gairdner International Award, the Helis Award, the Science of Oncology Award from the American Society of Clinical Oncology, and the Princess Takamatsu Award from the American Association for Cancer Research. He is a member of the National Academy of Sciences, the National Academy of Medicine, the American Society of Clinical Investigation, and the American College of Physicians, and a Fellow of the AACR Academy. Kaelin serves as vice-chair of Scientific Programs on the Damon Runyon Cancer Research Foundation Board of Directors, chair of the Damon Runyon Physician-Scientist Training Award selection committee, and is a member of the board of directors at Eli Lilly and the Stand Up to Cancer scientific advisory committee. Kaelin is recognized for his expertise in cancer biology, oxygen sensing, and targeted therapies.