The first group consists of ICIs inhibiting cytotoxic T lymphocyte-associated protein 4 (CTLA-4) on T cells [2, 3], the second one is related to programmed cell death 1 (PD-1) receptor on lymphocytes [4], and the third group is linked to programmed cell death ligand 1 (PD-L1) on tumor cells. The gene discussed is CTLA4; the disease is neoplasm.