ROS1 and non-small cell lung carcinoma: Lung cancer is a major cause of cancer-related deaths, and the most common type (85%) is non–small cell lung cancer (NSCLC).1,2 Treatment of patients with advanced-stage NSCLC (aNSCLC), ie, stage IIIB or IV, who harbor EGFR, BRAF, MET, RET, NTRK, KRASG12C, ALK, or ROS1 alterations with targeted therapies has improved survival.3–5 According to guidelines, patients with aNSCLC should undergo broad genomic profiling with next-generation sequencing (NGS) to inform treatment decisions.6,7