Chemokines involved in monocyte recruitment, such as CCL2/MCP-1, CCL3/MIP-1α, and CCL5/RANTES, are readily detectable at the site of inflammation (96, 166), and blood monocytes from patients with RA express the corresponding chemokine receptors CCR1, CCR2, CCR3, and CCR5 (15). Here, CCR5 is linked to rheumatoid arthritis.