TNF and Crohn disease: Deregulation of TNF signaling pathways has been implicated in the pathogenesis of several diseases, including rheumatoid arthritis (RA), Crohn's disease (CD), inflammatory bowel disease (IBD) and multiple sclerosis (MS), and hence therapeutic agents that target and block the activity of TNF have been developed for clinical use [21], [23], [24], [25], [26], [27], [28].