ROS1 and lung cancer: Furthermore, we found mRNA overexpression of ROS1 (10.136-fold), ROS1_ex18-24 (8.808-fold), ROS1_ex21-24 (13.031) and ROS1_ex8-12 (8.049-fold) in the ALK-positive lung cancer samples compared to the corresponding pericarcinous tissues (P < 0.05), especially cases 3, 4 and 5.