Accordingly, the concentration of fasting blood glucose was significantly reduced in both iron-treated Tmprss6−/−and Tmprss6+/+ mice, in which the resistance to diet-induced obesity was more exacerbated, but not in Tmprss6−/−mice compared with wild-type mice (Fig. 4b). This evidence concerns the gene TMPRSS6 and obesity due to melanocortin 4 receptor deficiency.