We found, for the first time, that the increased (P<0.05) circulating levels of IL-36γ in patients with obesity decreased (P<0.001) after weight and fat loss achieved by Roux-en-Y gastric bypass and that gene expression levels of IL36G were upregulated in the visceral AT (P<0.05) and in the peripheral blood mononuclear cells (P<0.01) from patients with obesity. This evidence concerns the gene IL36G and obesity due to melanocortin 4 receptor deficiency.