Setmelanotide is prescribed for the treatment of rare genetic diseases of obesity caused by certain variants of the genes encoding for pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) all of which cause a deficiency of these molecules [23]. The gene discussed is POMC; the disease is obesity due to melanocortin 4 receptor deficiency.