Univariate Cox proportional hazards analysis of intrinsic subtypes identified only the HER2+/HR- subtype as differing in breast cancer-specific survival compared with the luminal A subtype (hazard ratio =2.41, 95% CI = 1.24 to 4.70), but there were no significant differences among subtypes in multivariate analyses after controlling for other clinical or tumor characteristics. Here, ERBB2 is linked to breast cancer.