For instance, thymidylate synthetase (TYMS) and other fluorouracil-associated enzymes (such as thymidine phosphorylase (TYMP) and dihydropyrimidine dehydrogenase (DPYD)) have been analyzed with respect to the local recurrence and development of metastasis of CRC after postoperative 5-fluorouracil (5-FU) chemotherapy [18]. Here, TYMS is linked to colorectal carcinoma.