Correlating with the development of obesity and IR, IL-6 serum levels showed an increment in hfd-fed WT mice that was blunted in Tg mice, indicating that KAP prevents systemic hfd-induced up-regulation of IL-6, with no effect on resistin and PAI-1 levels (Table 2). This evidence concerns the gene RETN and obesity due to melanocortin 4 receptor deficiency.