ERBB2 and breast cancer: Indeed, a recent systematic review has shown that hormone receptor‐positive HER2‐negative breast cancers demonstrate the lowest percentage of T‐cell infiltration and the lowest incidence of LPBC (6% vs 20% in the TN subtype).12 This might be explained by the fact that luminal tumors have low expression of major histocompatibility complex molecules and, on the other hand, estrogen receptors are promoting a TH2 immune reaction, thus rendering these tumors less immunogenic, leading to decreased T‐cell infiltration.13, 14