Our biologic therapies represent attempts to target specific components of the inflammatory cascade. For example, we now have medications that target specific kinds of lymphocytes. We have medications that are being looked at that target specific products of lymphocytes, such as TNF. And the way that this is altering our therapy as we move on into the future is that we may be able to define specific populations of patients with inflammatory bowel disease. For example, one subgroup of patients may be a subgroup where TNF is an exceedingly important agent and we would use a biologic therapy directed against TNF.

We may have another subgroup of patients - for example, with ulcerative colitis - where we need to improve our restitution of the mucosal surface, the lining of the bowel. And in those particular patients, growth factors may be very important. And we may have a population where, if we block recruitment of lymphocytes to an area of inflammation, that that particular biologic therapy may be the best therapy for a patient.

So I think we're moving into an avenue where we can really target our therapy to a much greater extent than we have in the past. Because of this, we are likely going to need to subgroup our patients.

One other feature, many of our therapies before, if we looked at endoscopic healing, that was not an expectation of the results of therapy. We were looking for symptomatic improvement, for decreased inflammatory markers, but the endoscopy didn't always follow along. You could not always demonstrate mucosal healing, whereas with some of our biologic therapies, we are now able to demonstrate that there is a degree of mucosal healing along with the symptomatic improvement. That may in turn affect the natural history of the disease.

And that's very exciting, because if we can prevent some of the stricturing disease, if we can prevent some of these complications, we've really done a lot. Not only improving the quality of life of a patient at an individual point in time, but also down the road, preventing complications and perhaps the need for further surgeries.