AZGP1 and obesity due to melanocortin 4 receptor deficiency: All these findings, together with our previous results demonstrating that the ZAG rs4215 SNP was significantly associated with obesity susceptibility in a northern Han Chinese population (Zhu et al., 2012), suggest that ZAG is closely linked to obesity in both humans and mice and that it plays an important role in the regulation of body weight and body fat.