Studies on peptides in individuals with PWS have predominantly focused on regulation of appetite and satiety, metabolic control, and behavior (see, for example, review [22,23]), and, consequently, neuropeptides such as OXT, ghrelin, and glucagon-like peptide-1 (GLP-1) have been extensively investigated in this context. The gene discussed is GHRL; the disease is Prader-Willi syndrome.