Last but certainly not least, fusion oncoproteins involving the TRKA, TRKB, and TRKC tyrosine kinases (which are encoded by NTRK1, NTRK2, and NTRK3, respectively) have been identified across nine tumor types, including sarcoma, melanoma, gliomas, thyroid, lung, colon, breast, head and neck cancers) [94]. The gene discussed is NTRK2; the disease is central nervous system cancer.