Using Dundee series, Kaplan–Meier curves were plotted for the three main intrinsic breast cancer subtypes (ER+ PR+/− HER2− corresponding to the luminal subtype; ER+/− PR+/− HER2+ to a HER2-amplified subtype; and ER− PR− HER2− to a triple-negative subtype). This evidence concerns the gene ERBB2 and breast cancer.