A molecular classification of NSCLC has emerged, besides histological classification, leading to new biological insights and targeted therapies directed towards specific molecular abnormalities found in small subsets of NSCLC, such as mutations in epidermal growth factor receptor (EGFR) and B-Raf proto-oncogene (BRAF) genes or translocations in anaplastic lymphoma kinase (ALK), Ret proto-oncogene (RET), or C-Ros-1 proto-oncogene (ROS1) genes [3,4]. The gene discussed is ROS1; the disease is non-small cell lung carcinoma.