NTRK1 and colorectal cancer: As another of the more common and first reported NTRK fusion mutations, TPM3-NTRK1 was initially identified in colorectal cancer (CRC) samples, and subsequent studies have confirmed that chromosomal rearrangements in this manner make patients with CRC highly sensitive to TRKA inhibitors (Martin-Zanca et al., 1986; Ardini et al., 2014; Créancier et al., 2015).