PDCD1 and neoplasm: It was reported that the proportion of mTNBC with CPS ≥10 was about 38% in the KEYNOTE 355 study (19) and PD-L1 expression on tumor-infiltrating immune cells was ≥1% [VENTANA PD-L1 SP142 immunohistochemical testing (27)] was about 41% in the IMPASSION 130 study (18), which still meant that only a small population would benefit from PD-1 or PD-L1 antibodies.