TNF and rheumatoid arthritis: The current drugs for treating RA, such as disease-modifying anti-rheumatic drugs (methotrexate), nonsteroidal anti-inflammatory drugs (NSAID), steroids (prednisone), glucocorticoids, immunosuppressants, and biological therapies (TNF-α and IL-1 activity blocking monoclonal antibodies), have dramatically improved prognosis2,3.