The function of Ensembl gene identifier ENSG00000177000 (MTHFR, methylenetetrahydrofolate reductase) is as follows. Catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a cosubstrate for homocysteine remethylation to methionine (PubMed:29891918). Represents a key regulatory connection between the folate and methionine cycles (Probable). {ECO:0000269|PubMed:25736335, ECO:0000269|PubMed:29891918, ECO:0000305}.