PDCD1 and neoplasm: Responsiveness to anti-PD-1 antibodies such as pembrolizumab and nivolumab or to anti-PD-L1 antibodies atezolizumab, durvalumab, and avelumab may be predicted by the PD-L1 expression on tumor cells (TCs) and/or tumor-infiltrating immune cells (ICs) [3, 4].