Furthermore it has been shown to play a role in macrophage polarization, influencing a switch from M1 to M2 with studies demonstrating that inhibition of PPARγ in myeloid cells prevents polarization to an M2 phenotype predisposing to diet-induced obesity, insulin resistance and decreased fatty acid utilization [33]. This evidence concerns the gene PPARG and obesity due to melanocortin 4 receptor deficiency.