TNF and Crohn disease: Increasing knowledge regarding the pathophysiology of specific chronic inflammatory diseases and, specifically, inflammatory bowel disease (IBD) (consisting of Crohn’s disease (CD) and ulcerative colitis (UC)), psoriasis (PsO) and rheumatoid arthritis (RA), has provided insights into the underlying mechanisms that maintain the inflammation, such as the mechanisms promoted by Tumor Necrosis Factor Alpha (TNFα) [5].