Among these proinflammatory cytokines, IL-18 is considered a host defense protein against bacterial, fungal, and protozoan infections and has been shown to be overexpressed in autoimmune and inflammatory diseases, including inflammatory arthritis, insulin-dependent diabetes mellitus (IDDM), multiple sclerosis (MS), inflammatory bowel disease (IBD), pulmonary disease, and other inflammatory diseases [34]. This evidence concerns the gene IL18 and inflammatory bowel disease.