Fig. 1.

Genes involved in folate-associated one-carbon metabolism. Abbreviations: CBS cystathionine-β-synthase, DHFR dihydrofolate reductase, FOLR1 folate receptor isoform 1, GIF gastric intrinsic factor, MAT2A methionine adenosyltransferase isoform 2 (non-liver), MTHFD1 methylenetetrahydrofolate dehydrogenase/methynltetrahydrofolatecyclohydrolase/formyltetrahydrofolate synthetase, MTHFR methylenetetrahydrofolate reductase, MTR methionine synthase, SHMT serine hydroxymethyltransferase, SLC19A1 solute carrier family 19 (folate transporter) member 1 (also called the reduced folate carrier 1 (RFC1)), TYMS thymidylate synthase