In this study, we took the most extreme groups of patients that fall within prognostic stage IB breast cancer—those with anatomic pathologic stage IIIA-B (pT3N1 or pT1-3N1, grade 1–2 HR+/HER2- BC) and those with T1N0, G2–3 TNBC. This evidence concerns the gene ERBB2 and breast cancer.