ROS1 and non-small cell lung carcinoma: The NTRK (neurotrophic tyrosine receptor kinase) family, including NTRK1, NTRK2, and NTRK3, comprises a group of transmembrane tyrosine kinases that play a critical role in neural development.53 In NSCLC, NTRK fusions are rare but recurrent oncogenic drivers, estimated to occur in a range of 0.1–0.2%, and typically do not overlap with other oncogenic drivers such as EGFR, ALK or ROS1.