PDCD1 and non-small cell lung carcinoma: In the past few years, immune checkpoint inhibitors (ICIs) targeting programmed cell death 1 (PD-1), its ligand 1 (PD-L1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) have revolutionized the management of many types of solid tumors including NSCLC (2).