TNF and obesity due to melanocortin 4 receptor deficiency: IL-6 does not only negatively regulates the production of these cytokines, but it also induces the production of IL-1 and TNF antagonists in U937 cells.38 Furthermore, IL-6 can act to prime myeloid cells for IL-4 signaling during obesity in mice.39 As obese adipose tissue is described to be in an inflammatory state, we have checked the effect of adipocytes on cytokine production in an inflammatory environment using LPS-treated macrophages.