TYMS and cancer: ENOSF1 catalyzes the dehydration of sugars, including ribonic acid44, and has been investigated in the cancer field because ENOSF1 expression is elevated in cell lines resistant to thymidylate synthase (TS) inhibitors, such as 5-fluorouracil (5-FU), a chemotherapeutic drug used for the treatment of many types of cancers45.