PDCD1 and non-small cell lung carcinoma: Following the Phase III CheckMate-017 trial that evaluated the PD-1 inhibitor Nivolumab in metastatic non-small cell lung cancer (NSCLC) after prior platinum-based chemotherapy, the U.S. Food and Drug Administration (FDA) has fast-tracked the approval of Nivolumab to extend its use to patients with previously treated metastatic NSCLC, regardless of PD-L1 expression3.