For example, excess fat tissue in obese individuals is associated with high levels of inflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interleukin 1 (IL-1) 1, interleukin 6 (IL-6), and C-reactive protein (CRP), all of which are known mediators of RA (27, 28). This evidence concerns the gene CRP and rheumatoid arthritis.