Additionally, activation of Toll-like receptor 4 and 5 activation induced HGF production in human monocytes, which may amplify IL-6-mediated inflammation.<h4>Conclusion</h4>HGF primarily acts on synovial fibroblasts, driving an IL-6-mediated inflammatory amplification loop that may contribute to therapeutic resistance in RA. This evidence concerns the gene IL6 and rheumatoid arthritis.