Immune checkpoint blockers (ICBs), such as cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and programmed cell death 1 (PD-1) inhibitors, exert revolutionary effects on several tumors, while the efficacy seems to be closely related to the tumor immune microenvironment (TIME) (6, 7). The gene discussed is PDCD1; the disease is neoplasm.