This model of colitis is driven by the production of Th2 cytokines, such as interleukin-4 (IL-4) and IL-13, and recapitulates the disease features of human UC in terms of histological findings, affected site of injury (i.e., rectum), and Th1/Th2 cytokine balance2, 3. The gene discussed is IL4; the disease is colitis.