The majority of patients with IBD can be managed with currently available therapy, but the currently available agents do not seem to alter the natural history of the disease. An explosion of information about the immune system and the mediators of inflammation has now generated a host of new strategies that will likely benefit patients with IBD as well as patients with other chronic inflammatory and autoimmune disorders. Molecules of the immune system are being harnessed to treat disorders of the immune system. Some of these new concepts and therapies have been discussed here. Some are already in clinical trials, others have yet to be tried. As more specific immune modulators are tested in patients, it is likely that some will be effective in Crohn's disease but not ulcerative colitis and vice versa, due to, and revealing, the differences in the pathogenesis of these two diseases. The hope is that the application of these new modalities will alter the natural history of these diseases to the benefit of our patients.