NTRK1 and colorectal neoplasm: It has been confirmed that ALK, RET and NTRK1–3 gene rearrangements are very frequent in KRAS/NRAS/BRAF mutation-negative CRCs, especially in patients aged above 50 years, although these events may also occur in colorectal tumors carrying RAS/RAF mutations as well as in non-colorectal MSI-positive CRCs.