ERBB2 and breast cancer: To this end, RNA was extracted from BC cell lines (MCF10A and CA1, which mimic the normal breast and IDC, respectively), and five other IDC cell lines corresponding to different molecular subtypes of BC, including MCF7, BT474, SKBR3, MDA-MB-231, and MDA-MB-468 (which corresponds to lumA, lumB, HER2, TNBC, and TNBC subtypes, respectively).