ROS1 and cancer: Crizotinib is an ATP-competitive inhibitor targeting ALK/ROS1/c-MET kinases, which has been approved by the Food and Drug Administration (FDA), the European Medicines Agency (EMA), and the Pharmaceuticals and Medical Devices Agency (PMDA) as a first-in-class chemical for the treatment of NSCLC and other cancers with ALK rearrangement, ROS1 rearrangement, or aberrant activation of c-MET [24–27].