TGF beta and MMP3 are both targets already used in the clinic for monitoring RA progression as current or potential therapies due to their known contribution to joint and cartilage destruction33,34 whereas proteoglycans such as PRG4, secreted from the synovial fibroblasts, are involved in cartilage lubrication providing an anti-inflammatory effect35. This evidence concerns the gene PRG4 and rheumatoid arthritis.