The added disulfide bond reportedly increases the thermodynamicstability and decreases the proteolytic lability of the FGF21 moiety.45 This FGF21 analog has been tested in adultswith obesity with mild hypertriglyceridemia who were treated for 12weeks with three injections of BOS-580 given every fourth week. The gene discussed is FGF21; the disease is obesity due to melanocortin 4 receptor deficiency.