A recent study that used incretins (GLP-1 and Exendin-4) radiolabeled with technetium-99m showed that the tracer was highly taken up both by the liver and the pancreas and that the uptake was reduced in both organs after diet-induced obesity (DIO), similarly to alloxan diabetes controls [175]. The gene discussed is GCG; the disease is obesity due to melanocortin 4 receptor deficiency.