Thymidine phosphorylase precursor (TYMP) is a platelet-derived endothelial cell growth factor that catalyzes the formation of thymine and 2-deoxy-D-ribose-1-phosphate from thymidine and orthophosphate. TYMP is an angiogenic inducer that potently stimulates the growth of endothelial cells and induces chemotaxis. TYMP has a highly restricted target cell specificity acting only on endothelial cells. An increased expression of TYMP is found in a broad array of different solid tumors and inflammatory diseases and is frequently associated with poor prognosis. Mutations in the TYMP gene are linked to mitochondrial neurogastrointestinal encephalomyopathy.
