Clinical practice guidelines recommend routine testing for EGFR mutations, ALK fusions, and ROS1 alterations23-25 and the inclusion of NTRK1–3, ERBB2, MET, BRAF, KRAS, and RET in NGS panels.25 Our analysis demonstrates that patients with TRK fusion–positive lung cancers had better outcomes on larotrectinib compared with prior systemic therapy, supporting early testing. This evidence concerns the gene ROS1 and lung carcinoma.