Mechanistic studies of TET1 in obesity revealed that vitamin C intervention improved the lipid metabolic status of TET1-deficient mice fed an HFD, reversed adipocyte hypertrophy in TET1 haploinsufficient mice, and effectively prevented Tet1-deficiency-induced lipid accumulation associated with methylation of the PPARα gene promoter (81). This evidence concerns the gene TET1 and obesity due to melanocortin 4 receptor deficiency.