Also crizotinib has shown potent antitumor activity in a second subgroup of patients with non-small-cell lung cancer (NSCLC)—those with advanced ROS1 protooncogene receptor tyrosine kinase- (ROS1-) rearranged tumors, which are found in about 1% of NSCLC patient adenocarcinomas [36]. This evidence concerns the gene ROS1 and adenocarcinoma.