Although a direct participation of chymase or tryptase in obesity or diabetes has not been tested in any experimental model, cysteinyl protease cathepsins — which are indirectly regulated by chymase and tryptase [11], [12] — have been confirmed in diet-induced obesity and diabetes and in genetically-generated obesity and diabetes. The gene discussed is CMA1; the disease is obesity due to melanocortin 4 receptor deficiency.