Activated synovial fibroblasts produce inflammatory cytokine IL-6 and chemokine IL-8, as well as matrix metalloproteinases and other tissue destructive factors, which could, in turn, recruit macrophages and polarize them into M1 type in a positive feedback loop, leading to continued exacerbation of inflammation during the progression of RA [16]. This evidence concerns the gene IL6 and rheumatoid arthritis.