TYMP and cancer: UFT and capecitabine are both orally bioavailable prodrugs that are converted to 5-fluorouracil (5-FU) through several enzymatic steps (acylamidase isoenzyme A, cytidine deaminase, and the cytochrome P(CYP)450 system in the liver), the last of which is mediated by thymidine phosphorylase (TP) in cancer cells 10, 11.