Since immunotherapy targeting T cells normalizes glucose homeostasis9, and as T cell inhibitors reduce CD8+ T cells and proinflammatory macrophages in visceral adipose tissue25, we investigated whether abrogating IL-6 signalling in T cells would affect the development of obesity-associated tissue inflammation and, subsequently, alter systemic glucose homeostasis. Here, IL6 is linked to obesity due to melanocortin 4 receptor deficiency.