Jennifer Ligibel, MD, is a Professor at Harvard Medical School and a Senior Physician in the Breast Oncology Center at the Dana-Farber Cancer Institute. Dr. Ligibel has conducted extensive research evaluating the impact of exercise and weight loss interventions on cardio-respiratory fitness, biomarkers associated with cancer risk and outcomes, body composition, and quality of life in people who have or have had cancer. Her work resulted in the implementation of the Breast Cancer Weight Loss (BWEL) Trial, the only Phase III clinical trial designed to test the impact of a weight loss intervention on invasive disease-free survival in women with early-stage breast cancer and obesity.