IL6 and obesity due to melanocortin 4 receptor deficiency: In particular, pro-inflammatory macrophage accumulation in adipose tissue is an important feature of obesity, correlating with local expression of inflammatory markers including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) and C-C Motif Chemokine Ligand 2 (CCL2) [1,2,3,4].