IL6 and obesity due to melanocortin 4 receptor deficiency: Previous studies have shown that deficiency of IL‐6 is causing mature onset obesity,7, 8, 10 and the results of several studies involving central IL‐6 administration indicate that this anti‐obesity effect is exerted at the level of the brain.6, 20, 32 In addition, there is evidence that brain IL‐6 is crucial in the anti‐obesity signalling of both GLP‐1 analogues and amylin analogues.33, 34, 35, 36 These functions of IL‐6 are of clinical relevance, given that both GLP‐1‐ and amylin analogues are widely used for treatment of diabetes and obesity.37, 38