IL6 and obesity due to melanocortin 4 receptor deficiency: The low-grade systemic inflammation observed during obesity is especially manifested in adipose tissue and associated with increased levels of inflammatory mediators such as tumor necrosis factor-α, interleukin-6 (IL-6) and murine keratinocyte-derived chemokine (mKC, the murine ortholog of human interleukin-8) in circulation as well as in intra-abdominal adipose depots [4], [5], [6].