Mitochondrial methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), a mitochondrial enzyme involved in the metabolism of folate,9, 10, 11 is a bifunctional enzyme located in the mitochondria with methylene dehydrogenase and cyclohydrolase activities.12, 13 More recently, studies showed that MTHFD2 could confer redox homeostasis and promote caners cell growth, metastasis and correlate with poor survival.14 MTHFD2 suppression decreased tumour burden and prolonged survival.15, 16 To date, the relationship between overexpression of MTHFD2 and the development of NSCLC is still unknown. Here, MTHFD2 is linked to non-small cell lung carcinoma.