Although not yet studied in HER2-positive breast cancer cell lines, the T-type Ca2+-channel Cav3.1 is a key mechanism by which cyclophosphamide induces apoptosis in luminal MCF-7 breast cancer cells [64] and Cav3.2 is essential in the inhibitory effects of epigallocatechin-3-gallate on the viability of MCF-7 breast cancer cells [65]. This evidence concerns the gene ERBB2 and breast cancer.