TK1 and colorectal carcinoma: The study has also demonstrated that FOXM1 can potentially regulate other 5-FU targets, such as thymidylate synthase (TYMS), thymidine kinase 1 (TK-1) and thymidine phosphorylase (TYMP); inhibiting FOXM1 leads cell cycle arrest, DNA damage, and apoptosis in CRC cell lines (280).