ERBB2 and cancer: The cells used in the experiments were primary normal human mammary epithelial cells (HUMEC), MCF10 immortalized normal human mammary epithelial cells, T47D cancer cells (Luminal A type; ER+, PR+/−, HER2−), BT474 cancer cells (Luminal B type; ER+, PR+/−, HER2+), MDA-MB-468 cancer cells (MM468, Basal A type; ER−, PR−, HER2−), MDA-MB-231 cancer cells (MM231, Basal B type; ER−, PR−, HER2−, claudin-low), and SKBR3 cancer cells (HER2-overexpressing).