PDCD1 and non-small cell lung carcinoma: The programmed cell death-1 (PD-1) inhibitor pembrolizumab is approved as monotherapy for newly diagnosed advanced NSCLC patients with a programmed cell death-ligand 1 (PD-L1) tumor proportion score (TPS) of at least 50%, and without a targetable oncogene such as ALK and EGFR [3,4], improving the clinical outcomes compared with the platinum-based chemotherapy (CT) [5].