The univariate analysis of BCSM according to tumor subtype showed significant differences between MBC and FBC, with higher mortality in HoR-positive/HER2-positive males than females with the same subtype (5.0% vs. 2.4%, HR = 2.144 (1.016, 4.526), p = 0.016). The gene discussed is ERBB2; the disease is neoplasm.