APOE and obesity due to melanocortin 4 receptor deficiency: Moreover, we have employed APOE*3-Leiden.CETP mice to show that newly developed experimental drugs for obesity and diabetes, such as a fibroblast growth factor 21 (FGF21) analogue (91), a glucagon-like peptide 1 (GLP-1) receptor agonist (92), and the combination of a GLP-1 receptor agonist with a glucose-dependent insulinotropic polypeptide (GIP) receptor agonist, also have lipid-lowering and atheroprotective effects (93).