PDCD1 and non-small cell lung carcinoma: Recently, the five-year outcomes of KEYNOTE-024 were reported [1], and pembrolizumab (PD-1 inhibitor) could significant improved overall survival (OS) by 38% and progression-free survival (PFS) by 50% in patients with metastatic non-small lung cancer (NSCLC) with PD-L1 tumor proportion score (TPS) ≥ 50% compared with chemotherapy.