ADIPOQ and obesity due to melanocortin 4 receptor deficiency: It has been reported that the plasma adiponectin levels are decreased in humans under the conditions of obesity and/or diabetes mellitus.11 However, it was reported that plasma levels of adiponectin in the mice are not decreased in response to high-fat feeding for several weeks.39 Therefore, we used adiponectin-deficient mice to elucidate the role of adiponectin on colonic epithelial proliferation and carcinogenesis under the high-fat diet.