Targeting the cell of origin to prevent ER+ breast cancer

The incidence of estrogen receptor positive (ER+) breast cancer continues to increase and remains the most prevalent breast cancer subtype worldwide. To decrease breast cancer cases, novel preventative therapies and preclinical models that phenocopy ER+ breast cancer are needed. The cell of origin of ER+ BCa is a suggested drug target for breast cancer prevention. This thesis analysed the mammary stem and progenitor epithelial cell subsets that change upon ER+ breast cancer risk factor exposure to assist in identifying the cell of origin of ER+ breast cancer which is thought to be the ER+ luminal progenitor (LP) cell subset.