APOE and obesity due to melanocortin 4 receptor deficiency: As mentioned earlier, miR-155 and miR-221 were the only miRNAs modulated in all four HRDs; and miR-155 deletion in our ApoE-/- mice led to a new MHO model, whereby obesity, NAFLD, and hyperinsulinemia without insulin resistance were present along with reduced atherosclerosis.