Glucagon-like peptide-1 (GLP-1) receptor agonists are a class of drugs developed initially for treatment of type 2 diabetes (T2D) and then obesity, by mimicking the incretin effect which includes glucose-dependent increased insulin secretion and improved glycaemic control, and inducing weight loss in a dose-dependent manner [1]. The gene discussed is GLP1R; the disease is obesity due to melanocortin 4 receptor deficiency.