TLR2 and obesity due to melanocortin 4 receptor deficiency: Interestingly, several studies have demonstrated that TLR2-deficiency attenuates local inflammatory cytokines in the liver and adipose tissue, thus protecting mice from diet-induced insulin resistance, obesity, and hepatic steatosis (Himes and Smith, 2010; Kellermayer et al., 2011), suggesting TLRs may have a general function in mediating metabolic diseases.