MTR and keloid: Heat maps showed decreased expression of genes involved in Hcy catabolism, including CBS, MTR, 5-methylenetetrahydrofolate homocysteine methyltransferase reductase (MTRR), methylenetetrahydrofolate reductase (MTHFR), and methionine adenosyltransferase 1a (MAT1A) in keloids (Fig. 1G).