MTHFD1 and nasopharyngeal carcinoma: MTHFD1 (Methylenetetrahydrofolate Dehydrogenase, Cyclohydrolase and Formyltetrahydrofolate Synthetase 1) was found to be underexpressed in the cerebral cortex of NPC mice compared to WT mice, and the protein TYMS (thymidylate synthase) was found to be overexpressed in the cerebral cortex of NPC mice.