Geoff Lindeman, a clinician-scientist, is Joint Head of the Stem Cells and Cancer Division at the Walter and Eliza Hall Institute and a medical oncologist at The Peter Mac and Royal Melbourne Hospital. His laboratory is studying molecular regulators of normal mammary gland development and cancer, with a particular interest in understanding how mammary stem cells and their progeny contribute to the mammary gland development and cancer. The recent discovery of RANK-positive progenitors as a target for breast cancer prevention in BRCA1 mutation carriers has led to an international prevention study, BRCA-P. His laboratory is also using patient derived xenograft and tumour organoid models to test promising anti-cancer agents. This work has led to early phase studies of the BCL-2 inhibitor venetoclax in breast cancer.