TNF and Arthritis: The acute inflammation phase of arthritis has been well mimicked by the intra-articular injection of zymosan, which is accompanied by an increased profile of proinflammatory cytokines, such as interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-α) and IL-6, prominent infiltration of neutrophils and joint swelling that are used to investigate the effects of a variety of drugs (3).