This causes accumulation of SAH and inhibition of DNA methyltransferases, leading to decreased DNA methylation.15, 16 H19 expression is normally negligible in adult liver, but an elevated expression was noted in human patients with T2D.17 Given that excessive hepatic gluconeogenesis contributes significantly to the hyperglycemia in T2D,12 we hypothesized that H19 may have a role in gluconeogenesis regulation. Here, H19 is linked to type 2 diabetes mellitus.