PDCD1 and non-small cell lung carcinoma: Immune checkpoint inhibitors (ICIs), such as cytotoxic T-lymphocyte–associated protein 4 (CTLA-4) and programmed cell death protein-1 (PD-1)/programmed cell death ligand-1 (PD-L1) inhibitors, produce durable clinical responses in various solid tumors, including non-small cell lung cancer (1, 2).