One present limitation is that these new therapies, though being beneficial in a large number of CD patients, will not be beneficial to all CD patients. Presently treatment responders and non-responders can not be identified prior to the treatment with the biological adalimumab representing an important unmet clinical need. Since adalimumab treatment can be accompanied by serious, potentially lethal, side effects, it would be a major advantage if future biomarkers could predict whether an individual will or will not respond to one or the other treatment.