ESR1 and breast cancer: Nevertheless, there was an association of CD8‐positive lymphocyte infiltration with increased BC‐specific survival in ER‐positive/HER2‐positive tumors.53 A systematic meta‐analysis was recently performed by Mao et al including 22 964 BC patients from 22 studies and demonstrated, as in our study, that infiltrating CD8‐positive lymphocytes were correlated with better DFS and BCSS, but not OS, in the overall population.