However, it has been proposed that three main features must be present for disease to occur: (1) a genetically susceptible mucosal immune system; (2) an antigen, or pro-inflammatory compound, which reaches the gut and can trigger the susceptible immune system; and (3) an alteration in gut barrier function which allows this antigen to have contact with the mucosal immune system.19 In this regard the IL10 deficient mouse is an interesting model of human Crohn’s colitis. Here, IL10 is linked to Crohn's colitis.