ROS1 and non-small cell lung carcinoma: Examples of successful matching of tumor molecular alterations to cognate drugs include: NTRK inhibitors larotrectinib and entrectinib in multiple solid tumors with NTRK fusions1,2, ROS1 inhibitors entrectinib and crizotinib in non-small cell lung cancer (NSCLC) with ROS1 alterations3,4, and the FGFR inhibitor erdafitinib in FGFR-altered urothelial carcinoma5.