In this chapter, we speculate about fertile areas of research in Crohn's disease. The first section focuses on the etiopathogenesis of Crohn's disease, reflecting on old work in the field and how it can be placed in a modern immunological context. The remainder of the chapter bridges bench research in inflammatory bowel disease with strategies to treat patients. Special attention is paid to ways in which patients can be stratified to predict natural history of disease and response to treatment based on genetic and biochemical data. Figure I is an overview of these strategies.