In this context, tumor necrosis factor-alpha (TNF-α) released mainly by macrophages is a central pro-inflammatory cytokine involved in the pathogenesis of both RA and OA, promoting the recruitment of immune cells into the synovium and stimulating the release of additional inflammatory mediators by synoviocytes and chondrocytes that perpetuate the inflammatory cycle [19,21]. This evidence concerns the gene TNF and rheumatoid arthritis.