Better for examining the metabolic syndrome are the established atherosclerosis models such as ApoE-/- mice (apolipoprotein E deficient) and Ldlr-/- mice (LDL receptor deficient); these animals are predisposed to hypercholesterolemia, atherosclerosis, and obesity, and on a HFD or Western diet will also develop NAFLD/NASH (153). Here, APOE is linked to obesity due to melanocortin 4 receptor deficiency.