IL6 and obesity due to melanocortin 4 receptor deficiency: Although the total number of eWAT infiltrating macrophages (F4/80+CD11b+) was similar between WT and IFNAR−/− mice, lack of IFNAR signaling reduced percent of macrophages producing proinflammatory cytokines central to obesity pathogenesis5 (IL-6 and TNF; Fig. 4g; Supplementary Fig. 7; Supplementary Table 1).