Interestingly, some of the mediator marks could be linked to specific genes that were reported earlier to play a role in the development of weight gain/obesity, insulin resistance/diabetes, cardiovascular disease, and/or fetal growth retardation: UQCRC2, MTNR1B, GRIN2A, FABP4, and LRP8. FABP4 encodes for a member of the fatty acid-binding protein family regulating lipid trafficking, signaling, and metabolism. The gene discussed is MTNR1B; the disease is obesity due to melanocortin 4 receptor deficiency.