TGFβ is especially important in the regulation of T-cell responses, promoting differentiation of both Foxp3+ regulatory T cells (Tregs) and T helper type 17 cells, and suppressing the differentiation of T helper type 1 and T helper type 2 cells.2 Indeed, recent evidence suggests that targeting the TGFβ pathway in IBD may have beneficial effects in some patients.3 Many different cells in the gut produce TGFβ, but always as a latent complex, which has to be activated to function. This evidence concerns the gene FOXP3 and inflammatory bowel disease.