IL10 and colitis: In addition, the gene transduction step would proceed ex vivo, negating concerns about viral and retroviral vector use in human subjects.81 Furthermore, Tregs in themselves have been shown to play a beneficial role in maintaining immune control of the intestinal mucosa, with IL-10 playing an essential role in their activation and function.82–84 The gut-specific regulatory function of IL-10 produced by these cells is seen in mice with Treg-specific ablation of a conditional IL-10 allele: these mice spontaneously develop colitis, but not systemic autoimmunity.85