OGT and obesity due to melanocortin 4 receptor deficiency: Consistent with this notion, transgenic animals overexpressing OGT or GFAT in the β cells of the pancreas, the liver, or in muscles and adipose tissue, develop phenotypes reminiscent of obesity or type 2 diabetes (hyperinsulinemia, hyperleptinemia, glucose intolerance, insulin resistance) [41, 42].