TNF and rheumatoid arthritis: During RA progression, FLS grow without contact inhibition following morphology changing, express high levels of biomarkers such as c-fos, Jun-B, egr-1 and matrix metalloprotease (MMP)-3 [6], and secretes several inflammatory cytokines, such as IL-6, IL-8, IL-1, TNF-α and MCP-1 [7, 8].