PDCD1 and breast neoplasm: Recent studies have revealed that PD-1 and PD-L1 expression levels in breast tumours are associated with adverse clinicopathological features.17 18 Based on these findings, several clinical trials targeting PD-1 and PD-L1 were recently conducted.19 Among patients who received neoadjuvant chemotherapy, PD-L1 expression in the epithelium was a significant predictor of pCR.20 Sabatier et al also reported that high PD-1 and PD-L1 expression was associated with better overall survival and higher pCR rates in TNBC.21