stem cell mammary stem cell A multi-fate stem cell that is the source of cells for growth of the mammary gland during puberty and gestation. This cell type gives rise to both the luminal and myoepithelial cell types of the gland, and have been shown to have the ability to regenerate the entire organ in mice. This cell type also plays an important role in carcinogenesis of the breast. This cell type is Lin-, CD24-positive, CD29-hi. [ PMID:16397499 GOC:tfm PMID:17851544 GOC:hjd PMID:15987436 ]