ROS1 and non-small cell lung carcinoma: The first-generation anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitor (TKI) crizotinib has multiple kinase inhibitory activities against ALK, MET, and ROS1, and it shows promising efficacy for non-small-cell lung cancer (NSCLC) patients carrying the ALK gene rearrangement1,2.