ROS1 and cholangiocarcinoma: Several ROS1 kinase fusion proteins have been identified, including the Fused in Glioblastoma–ROS1 (FIG–ROS) that was first discovered in a human glioblastoma cell line [18] and more recently in patients with NSCLC [19], cholangiocarcinoma [17], and serous ovarian carcinoma [18].