TLR4 and obesity due to melanocortin 4 receptor deficiency: Because fatty acids are directly implicated in the induction of inflammation in adipocytes via TLR4 activation [7], and circulating fatty acid concentrations are elevated in obesity, we further explored the possibility that fatty acids exert a direct role in the regulation of TLR2 and TLR4 expression, hence indirectly influencing the inflammatory response in adipocytes.