ERBB2 and breast cancer: On subgroup analyses according to breast cancer subtype, post-PST CD8+ TIL infiltration was associated with patients’ survival in HER2+ subtype (p = 0.174 for luminal A; p = 0.192 for luminal B; p = 0.033 for HER2+; p = 0.154 for triple-negative subtype, log-rank test).