We also found that the previously identified markers of obesity fructose-biphosphate aldolase B (ALDOB), betaine-homocysteine methyltransferase (BHMT), and haptoglobin (Hp) were upregulated more than 4-fold in the HFD mice (74), and that several members of the complement system (Cfd, C8g, C8a, and C8b) were significantly depleted. Here, BHMT is linked to obesity due to melanocortin 4 receptor deficiency.