IL1R1 and obesity due to melanocortin 4 receptor deficiency: [21]. In the current study, BMM isolated from UNS offspring have a significantly enhanced immunophenotype evidenced by secretion of large concentrations of IL-β and IL-6 accompanied by increased gene expression of TLR4, IL-1R1 and IL-6R. TLR4 plays a fundamental role in the innate immune system. It is activated in response to bacterial LPS, however given its propensity to also bind saturated fatty acids, it has been ascribed a role in the development of diet-induced metabolic dysfunction and obesity [25].