IL22 and cancer: The absence of IL-22 has been shown to exacerbate disease in dextran sulfate sodium (DSS)- or T cell-induced animal models of colitis.4 On the other hand, in certain animal models of colitis IL-22 has been shown to have a pro-inflammatory role.5,6 It should be noted that prolonged usage of IL-22 as a therapy may lead to the development of colitis-associated cancer.7–9 Thus, the effects exerted by IL-22 are complex, and more studies are needed to understand the functional dichotomy of the cytokine.