The unmasking of novel unipotent stem cells in the mammary gland

Abstract

Nature 479 7372, 189–193 (2011); published online October 09 2011 Mammary stem cells (MaSCs) have been prospectively isolated and shown to reconstitute a fully functional mammary gland in the mouse at the single cell level. These cells are self-renewing and can differentiate into all mature mammary epithelial cell types, thus fulfilling the defining characteristics of a stem cell. In a recent issue of Nature, Blanpain and colleagues (Van Keymeulen et al, 2011) add a new layer of complexity to the prevailing model of the mammary epithelial hierarchy through the recognition of novel unipotent stem cells that appear to maintain normal homeostasis of postnatal mammary epithelium. These data poin..