TLR2 and obesity due to melanocortin 4 receptor deficiency: These results were associated with reduction of FFA plasma concentration, known ligand of TLR2 and TLR4, suggesting that RSV may improve obesity-induced inflammation by both down-regulating TLR2 and TLR4 expression in epididymal adipose tissue and reducing plasma FFA levels in mice receiving a HFD [114].