ROS1 and cancer: Lung cancer is the most common cancer as well as the leading cause of cancer related deaths worldwide, with 2.09 million new cases and 1.76 million deaths in 2018.1 Nonsmall cell lung cancer (NSCLC) accounts for 85% of all lung cancer cases and almost two‐thirds have distant metastases at the time of diagnosis.2 Molecularly targeted agents against oncogenic drivers like EGFR, ALK, and ROS1 have revolutionized the treatment paradigm for a subset of NSCLC patients with these genomic alterations.