ERBB2 and cancer: Breast cancer was the most studied cancer type, with consistent dose‐dependent reductions in viability observed across hormone receptor‐positive (MCF‐7, BT474), HER2+ (AU565), and triple‐negative cell lines (MDA‐MB‐231, MDA‐MB‐436), with IC50 values ranging from 1.1 to 17.5 μM [36, 58, 63].