However, in pathological conditions such as obesity, dysfunctional adipocytes mostly produce and release pro-inflammatory adipokines such as leptin, tumour necrosis factor-α (TNFα), interleukin 6 (IL-6), interleukin 18 (IL-18), or resistin, which have atherogenic effects [4]. Here, RETN is linked to obesity due to melanocortin 4 receptor deficiency.