ROS1 fusions have been reported to affect different tumor types with different frequencies; for example, in the case of NSCLC, ROS1 fusions may be found in 1%–2% of the cases, while their involvement in other tumors, such as intrahepatic cholangiocarcinoma, seems more frequent, with frequencies reaching up to 37% [9, 22, 23]. Here, ROS1 is linked to non-small cell lung carcinoma.