CCL4 and rheumatoid arthritis: Several chemokines have been detected in RA synovium and include IL-8 (CXCL8) [3], monocyte chemoattractant protein 1 (MCP-1; CCL2) [4], epithelial neutrophil activating peptide 78 [5], macrophage inflammatory protein 1 alpha (MIP-1α; CCL3) [6], macrophage inflammatory protein 1 beta (MIP-1β; CCL4) [7], RANTES (CCL5) [7] and growth-related gene product alpha (GROα; CXCL1) [8] (reviewed in [9]).