In an attempt to dissect the mechanisms that suppress Sirt1 in IBD, we showed that stimulation of control intestinal mucosal cells with tumor necrosis factor (TNF)-α and interleukin (IL)-21 reduced Sirt1 expression while blockade of the activity of these two cytokines upregulated Sirt1 in IBD lamina propria mononuclear cells (LPMC) (10). This evidence concerns the gene IL21 and inflammatory bowel disease.