HFD-induced obesity is associated with the infiltration of macrophages into the adipose tissue, which accounts for a higher concentration of proinflammatory cytokines such as TNF-α and IL-6 in the adipose tissue, as well as an increase in inducible nitric oxide synthase (iNOS) expression [40,41]. The gene discussed is IL6; the disease is obesity due to melanocortin 4 receptor deficiency.