CD74 and non-small cell lung carcinoma: The ROS proto-oncogene 1 (ROS1) gene rearrangement has been identified in 1% to 2% of non-small cell lung cancer (NSCLC) patients.[1] To date, the known fusion partners of ROS1 include CD74, SDC4, and EZR.[2] With the increasing application of next-generation sequencing (NGS), more rare fusion genes have been identified, and these complex fusions and mutations may impact the effectiveness of drug therapy.