The idea that rhPRG4 negatively affects HA-CD44-induced invasiveness of cancer cells is consistent with other studies suggesting that PRG4 antagonizes HA-CD44-mediated inflammatory signalling that induce synoviocyte proliferation in rheumatoid arthritis and osteoarthritis diseases and a number of inflammatory cytokine production in human and murine macrophages [9,10,12]. This evidence concerns the gene CD44 and rheumatoid arthritis.