Testing for epidermal growth factor receptor (EGFR) mutations, anaplastic lymphoma kinase (ALK) rearrangement, c-ros oncogene 1 (ROS1) rearrangement and programmed death ligand 1 (PDL 1) testing are now highly recommended for all patients with NSCLC. The gene discussed is ROS1; the disease is non-small cell lung carcinoma.