Among these genes hepatocyte growth factor (HGF), tenascin-C (TNC), inhibitor of DNA binding 1 and 3 (ID1 and 3) and matrix metalloproteinase 13 (MMP13) were of special interest since they were downregulated by gold dissolucytosis and they are directly involved in RA pathogenesis. This evidence concerns the gene MMP13 and rheumatoid arthritis.