In an exploratory multivariate logistic regression analysis including the significant predictive markers from univariate analysis (biology-based tumor types, Ki67 labeling index, CK5/6 expression, grading, treatment arm; Table 2), the HR+/HER2+ subgroup was independently linked to a higher pCR rate (P = 0.046; compared to HR+/HER2-) while the HR-/HER2- group lost its predictive significance. The gene discussed is ERBB2; the disease is neoplasm.