TNF and rheumatoid arthritis: In synovial cells extracted from RA patients, it was found that knocking down TNFα could significantly reduce the production of other pro-inflammatory factors, such as IL-1β, IL-6, IL-8, granulo-macrophage colony-stimulating factor (GM-CSF), etc., thereby exerting anti-inflammatory and anti-rheumatic effects (Micheau and Tschopp, 2003).