RETN and obesity due to melanocortin 4 receptor deficiency: Further, adipose tissue is not only actively involved in energy balance, but also an important organ to produce various cytokines that are involved in inflammatory pathways, such as TNF-α, IL-6, ADPN and resistin.23,24 The adipose gene expression of proinflammatory (TNF-α, IL-6) cytokines is elevated with obesity,23 whereas the expression levels of ADPN are lower in obese individuals.25 Furthermore, there is a close link among obesity, a state of chronic low-level inflammation and oxidative stress.