Research Professor, Department of Medical Oncology & Therapeutics Research Rowan Chlebowski, M.D., Ph.D., is one of the most influential breast cancer researchers in the world. As a clinical breast oncologist with a Ph.D. in reproductive biology, he has a credentialed clinical and research interest in breast cancer therapy and prevention, menopausal hormone therapy influences on cancer and chronic disease, and lifestyle influences on breast cancer incidence and outcome.