TNF and rheumatoid arthritis: Approximately 0.5%–1% of the population has RA, and small joints are affected more frequently than large joints.3 RA is characterized by increased levels of inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-6, and interleukin-1, in the synovial joints.4 Currently, arthritis treatment focuses on controlling the symptoms, especially pain; there is no satisfactory prevention or cure.