Cytosolic and mitochondrial folate-mediated one-carbon metabolism and formate generation by ADH5 and ALDH2. ADH5, alcohol dehydrogenase 5; ALDH2, aldehyde dehydrogenase 2; DHF, dihydrofolate; DMG, dimethylglycine; dTMP, thymidylate; dUMP, deoxyuridine monophosphate; GSH, reduced glutathione; SAH, S-adenosylhomocysteine; SAM, S-adenosylmethionine; THF, tetrahydrofolate.