IL6 and obesity due to melanocortin 4 receptor deficiency: However, our findings that IL-1β and TNFα cooperatively amplify the expression of IL-6 in human and mouse adipocytes are novel, and not only show that both IL-1β and TNFα could induce IL-6 expression in adipocytes, but also demonstrate a mechanism as to how IL-1β/TNFα co-expression could lead to elevations in IL-6 levels in obesity setting.