GCG and obesity due to melanocortin 4 receptor deficiency: The clinical drugs for treating obesity include pancreatic lipase inhibitors, glucagon-like peptide 1 (GLP1) receptor agonists and dual agonists for GLP1 and glucose-dependent insulinotropic peptide (GIP) receptors, γ-aminobutyric acid (GABA) A type receptor activators, serotonin 2C receptor agonists, opioid antagonists, dopamine-norepinephrine reuptake inhibitors, etc. [12,13,14].