INS and obesity due to melanocortin 4 receptor deficiency: Obesity is accompanied by infiltration of proinflammatory macrophages into adipose tissue; these cells secrete inflammatory cytokines, such as TNFα, which generate insulin resistance by stimulating catabolic pathways (Hotamisligil, 2006; Lumeng et al., 2007; Ye and Keller, 2010; Ouchi et al., 2011).