The hierarchically organized mammary gland epithelium consists of differentiated luminal epithelial and basal myoepithelial cells, as well as undifferentiated stem cells and restricted progenitors. Breast cancer is a heterogeneous disease and, besides the nature and number of transforming events and microenvironmental factors, the differentiation state of the cell-of-origin of cancer determines the phenotype, tumorigenicity, and metastatic potential of this malignancy. Hence, it is of paramount importance to understand how the different cell types in the human breast/mouse mammary gland are maintained and regulated.
For these studies, we use in situ genetic lineage tracing, and CRISPR, shRNA, and transposon-based screens.
