AGER and obesity due to melanocortin 4 receptor deficiency: To explain the lower plasma levels of CML-AGE in patients with obesity vs. lean state, a model was developed in mice with genetically mediated diabetes (db/db mice); the results of studies in this model suggested that plasma levels of CML-AGE were lower in obesity on account of trapping of the RAGE ligand in the obese (high RAGE-expressing) adipose tissue.