At present, more compounds of receptors with dual agonists are being tested, for example, GLP-1R/GR (glucagon receptor), GLP-1R/AR (amylin receptor) and GLP-1R/NPYR (peptide YY binds to neuropeptide Y receptors) [57, 58], and might achieve further advances in T2DM, obesity and associated conditions therapy. The gene discussed is PYY; the disease is obesity due to melanocortin 4 receptor deficiency.