IL4 and colitis: Of the several animal models of intestinal inflammation, the well-characterized haptene reagent TNBS–induced colitis resembles human UC in its various histological features including infiltration of colonic mucosa by neutrophils and macrophages and increased production of inflammatory mediators including TH1 profile of cytokines.[11] Moreover, various experimental trials using antibodies to interleukin (IL)-12 and IL-4 gene transfer, have indicated that the TNBS-induced colitis model is useful to test new therapeutic strategies for humans.[12, 13]