Analysis of cytokine mRNA and protein in synovial tissues has revealed that a variety of pro-inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-1, and IL-6, as well as chemokines including CCL2 and IL-8 are upregulated in the peripheral blood and the joints of RA patients10. This evidence concerns the gene CCL2 and rheumatoid arthritis.