The effect of a casein hydrolysate on ghrelin release was reduced in mucosal segments of the human fundus, whereas the effect of the broadly tuned bitter agonist denatonium benzoate was apparently selectively blunted by obesity in human small intestinal—but not in fundic— segments [73,74]. The gene discussed is GHRL; the disease is obesity due to melanocortin 4 receptor deficiency.