TNF and obesity due to melanocortin 4 receptor deficiency: Compared to WT littermates, flow cytometric assay showed that the ATMs from Vsig4−/− obese mice expressed higher amounts of proinflammatory factors (like pro-IL-1β, IFN-γ, and TNF), which have been described to actively participate into the pathogenesis of HFD-caused obesity and insulin resistance26, 27 (Fig. 1i).