On the contrary, a variety of ROS1 re-arrangement or mutation were detected in various tumors, such as ROS1-EPHA7 fusion in breast cancer [49], ROS1-FN1 or ROS1-SLC12A2 re-arrangement in inflammatory myofibroblastic tumor [50, 51], ROS1-WNK1 or ROS1-CD74 fusion or ROS1-G2032R mutation in lung cancer [52–54]. Here, CD74 is linked to breast cancer.