The introduction of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and dual incretin agonists targeting both the GIP and GLP-1 receptors (GIP/GLP-1 dual agonists) has reshaped obesity management, approaching degrees of weight loss previously achievable largely through metabolic surgery. The gene discussed is GCG; the disease is obesity due to melanocortin 4 receptor deficiency.