ERBB2 and breast cancer: In subgroup analysis, subjects with HR+/HER2– subtype breast cancer in the married group showed improved OS (1.589, 95% CI: 1.363–1.854, p < 0.001) and BCSS (HR = 1.512, 95% CI: 1.255–1.82, p < 0.001) than those in the unmarried group.