The rapid inactivation of GLP-1 by the enzyme dipeptidyl peptidase IV (DPP-IV) within minutes prompted the development of GLP-1 analogs with prolonged half-lives, which are now approved for the treatment of T2DM and obesity (semaglutide, 160 h half-life). The gene discussed is DPP4; the disease is obesity due to melanocortin 4 receptor deficiency.