Increased serum concentrations of TNF, NO,and IL-6 are strongly associated with obesity [186, 187], and proinflammatory cytokines sourced from adipose tissueincluding TNF, and IL-6 are among several important factors that participate inthe development of insulin resistance and type 2 diabetes mellitus [188–191]. Here, TNF is linked to obesity due to melanocortin 4 receptor deficiency.