PDCD1 and non-small cell lung carcinoma: Evidence has shown that programmed cell death protein 1/death ligand 1(PD-1/PDL-1) signaling pathways play pivotal roles in tumor evasion during NSCLC progression, and when used as adjunctive therapy for NSCLC, PD-1 inhibitors can increase tumor suppression rates.3 Sintilimab, a PD-1 monoclonal antibody and novel PD-1 inhibitor, exhibits a high affinity for PD-1, thus achieving high, stable target occupancy.