TNF and Peptic ulcer: Persistent infection by H. pylori in the stomach induces the production of proinflammatory cytokines, such as interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α (3), which are closely associated with several gastroenterological diseases, including gastritis, peptic ulcer, and gastric adenocarcinoma (4, 5).