TLR2 and obesity due to melanocortin 4 receptor deficiency: In particular, TLR2 and TLR4 are highly expressed in macrophages and adipose tissue and can be activated by (saturated and oxidatively modified) fatty acids, elevated during obesity, resulting in NFκB-dependent differentiation with enhanced secretion of pro-inflammatory cytokines (e.g. TNFα) [7], [8].