PCSK1 and Obesity: Setmelanotide is another anti-obesity medication; however, it has been approved only for three ultra-rare genetic disorders that cause obesity: Pro-OpioMelanoCortin (POMC) deficiency, Proprotein Convertase Subtilisin and Kexin type 1 (PCSK1) deficiency, and LEPtin Receptor (LEPR) deficiency [29].