ROS1 and non-small cell lung carcinoma: The approval of effective oral small-molecule inhibitors of ROS1 in ROS1 fusion-positive (ROS1+) NSCLC has revolutionized its treatment paradigm.4-6 However, resistance to ROS1 tyrosine kinase inhibitors (TKIs) invariably occurs and causes disease relapse.7 Understanding the molecular mechanisms of resistance has been crucial in laying the groundwork for the development of next-generation ROS1 inhibitors and other novel strategies to tackle TKI-refractory disease.