While MCF-7 represents luminal type A breast cancer (ER+, PR+/−, HER2-), BT-474 represents luminal type B (ER+, PR+/−, HER2+) [33], and MDA-MB-468 is a triple-negative breast cancer (TNBC) cell line [34]. The gene discussed is ERBB2; the disease is breast carcinoma.