Moreover, CXCL5, which belongs to the chemokine family mainly regulating the chemotaxis of inflammatory cells (i.e., neutrophils), can be stimulated by TNF-α and is believed to be a mediator in an inflammatory process that links obesity to insulin resistance in mice [78], although Yang et al. reported that the elevated CXCL5 levels were associated with hypercholesterolemia, but not insulin resistance, in Chinese subjects [85]. Here, CXCL5 is linked to obesity due to melanocortin 4 receptor deficiency.