ICIs, for example programmed cell death-1 (PD-1) inhibitors such as nivolumab and pembrolizumab, programmed cell death ligand 1 (PD-L1) inhibitors such as atezolizumab, and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors such as ipilimumab, the ICI-based combination with TKIs, and VEGF-neutralizing antibody or systematic or local anti-tumor therapies, are being further studied in clinical trials. The gene discussed is PDCD1; the disease is neoplasm.