In obesity, oxLDL is recognized by toll-like receptor-4 (TLR-4) and plays a critical role in development of atherogenesis. Activation of TLR-4 enhances lipid uptake by macrophage thus develops foam cells [47]. Polarized M1 stimulates TLR-3, TLR-4 or TLR-9 and upregulates the expression of scavenger receptor A, macrophage receptor with collagenous structure (MARCO) and lectin like low-density lipoprotein receptor-1 (LOX-1), hence enhancing foam cell formation [48]. Here, TLR4 is linked to obesity due to melanocortin 4 receptor deficiency.