In the CheckMate 227 trial, a phase 3 open-label, randomized controlled study, patients with stage IV or recurrent NSCLC without EGFR/ALK/ROS1 alterations were randomized in a 1:1:1 ratio to receive ipilimumab and nivolumab, nivolumab alone (for PD-L1 ≥ 1%), nivolumab plus chemotherapy (for PD-L1 < 1%), or platinum-based chemotherapy. The gene discussed is ROS1; the disease is non-small cell lung carcinoma.