BRCA1 and neoplasm: To test this hypothesis, the PS signals on the cell membrane were investigated by FACS analysis from primary mammary epithelial cells in both WT and Brca1-MSK mice, using multiple cell lines without or with the expression of sgATP11b, including mouse Brca1-MT (G600) mammary epithelial cells, 545 Brca1-MT tumor cells, and 628 Brca1-MT tumor cells, as well as MDA-MB-436 and T47D BRCA1-WT cells.