Expression of DC-SIGN and its ligand, intercellular adhesion molecule (ICAM-3, mostly expressed in T cells), is substantially detected in RA synovium, suggesting that the interaction of macrophages/T cells via DC-SIGN/ICAM-3 promotes the additional activation of synovial CD68+ macrophages and production of extracellular matrix metalloproteinase inducer (EMMPRIN) and MMP-1 (56). This evidence concerns the gene CD68 and rheumatoid arthritis.