While cytokine blockade is currently applied for the treatment of inflammatory disorders, including for instance the use of antitumor necrosis factor-α monoclonal antibodies to treat ulcerative colitis and Crohn’s disease, it remains to be investigated whether a blockade of the IL-33/ST2 pathway may represent a valid approach for the therapy of established IL-33-dependent tumors. Here, IL33 is linked to ulcerative colitis.