ROS1 and cholangiocarcinoma: Recently, Gu et al. found a fusion of the ROS1 gene with the FIG gene in 2 out of 23 patients (8.7 %) with cholangiocarcinoma; the authors suggested that this could be a driver mutation, because it confers transforming activity to bile duct cells and can be effectively blocked with an ROS1 tyrosine kinase inhibitor [17].