PDCD1 and neoplasm: Immunotherapy with immune checkpoint inhibitors (ICIs), including antibodies against programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1), and cytotoxic T lymphocyte-associated protein 4 (CTLA-4), has achieved success in some tumor subgroups that lack targeted therapies, such as NSCLC without typical driver mutations (10).