Activation of TLR4 by saturated fatty acids elicits, through the activation of NFκB, the secretion of several proinflammatory cytokines such as TNF-α, IL-6, and MCP-1, which are involved in the development of obesity-associated inflammation and insulin resistance [128, 133, 134]. Here, CCL2 is linked to obesity due to melanocortin 4 receptor deficiency.