PDCD1 and non-small cell lung carcinoma: Immune checkpoint inhibitors (ICIs) targeting programmed cell death-1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) have transformed the therapeutic landscape of advanced NSCLC, achieving superior survival benefits compared with conventional chemotherapy.