IL6 and rheumatoid arthritis: RA causes FLS to display many biological characteristics such as aberrant growth, increased aggressiveness, and excessive secretion of inflammatory substances and cytokines, including TNF-α, IL-6, C-C chemokine ligand(CCL-2), Matrix metalloproteinase-3(MMP3), and vascular endothelial growth factor-alpha (VEGF-α).