STIM1 and breast cancer: The normal breast epithelial cell MCF10A, the ER+ breast cancer cell lines T47D and MCF7, the HER2 cell line SKBR3 and the TNBC cell lines BT20, MDA-MB-468, MDA-MB-231 and HS578T were treated with PNGase F, to remove N-linked oligosaccharides [42], or the vehicle and then subjected to Western blotting with specific anti-STIM1 or anti-Orai1 antibodies.