ICIs, such as anti-programmed cell death-1(PD-1), anti-programmed cell death-ligand 1 (PD-L1), and anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) [1,2,3] made significant progress in amplifying endogenous anti-tumor T cell responses. The gene discussed is PDCD1; the disease is neoplasm.