ROS1 and non-small cell lung carcinoma: Admittedly, ROS1 targeted inhibitors, represented by crizotinib, achieved tremendous success in ROS1-fusion cancers especially NSCLC (3, 4), but actually, rearrangement just accounts for a fairly small proportion of patients, less than 2% in NSCLC, and even lower in other malignancies (1, 25).