Great progress has been made over the last decade in the development of targeted specific therapies for inflammatory bowel disease. Nevertheless, accumulating experience with these modalities and results from ongoing investigations of agents currently on the market and those in development have demonstrated that efficacy may be limited to certain patient phenotypes. Recently, great interest has been applied to studies of the interplay between the adaptive and innate immune responses to achieve a better understanding of the immunopathogeneses of inflammatory bowel diseases as well as to identify targets for even more potent intervention.