ROS1 and non-small cell lung carcinoma: Recently, the drug Crizotinib (Pfizer’s Xalkori) successfully obtained FDA approval as a treatment for patients with NSCLC with MET exon 14 skipping which occurs in approximately 3% of NSCLC tumours and ROS 1/anaplastic lymphoma kinase-positive resistant systemic anaplastic large cell lymphoma (ROS-1/ALK-ALCL) [111].