TNF-α has a wide array of roles in host defence, including initiating a strong acute inflammatory response but limiting duration of inflammatory activation, and is the target of blocking monoclonal antibodies in the treatment of a wide array of autoimmune conditions including Crohn’s disease and RA.32 Six studies (n=2300) investigated TNF-α in GAD, with mixed findings. This evidence concerns the gene TNF and rheumatoid arthritis.