Professor Geoffrey Lindeman and his team identified breast stem and progenitor cells that generate all ductal tissue in the breast. His group’s discoveries helped define breast development from long-lived stem cells to progenitor and mature epithelial cells, providing a new framework for studying the molecular and cellular events that give rise to breast cancer. His group was the first to identify the culprit progenitor cell responsible for breast cancer in BRCA1 mutation carriers. In parallel, Lindeman has established a leading translational research program, made important contributions to tissue banking for cancer research, and helped advance research and clinical services in hereditary cancer.