Considered together, our data suggest that chemerin is produced at high levels by FLSs in RA synovium and that extracellular protease is produced by preexistent neutrophils and mast cells converted from inactive prochemerin into bioactive chemerin, which have powerful chemoattractant properties for migration of macrophages and DCs into the RA synovium. This evidence concerns the gene RARRES2 and rheumatoid arthritis.