In RA synovial fibroblasts, as well as in monocytes and chondrocytes, the pro-inflammatory cytokine TNF-α has been demonstrated to induce IL-8 mRNA expression and protein secretion [17–23], indicating that synovial fibroblasts stimulated with pro-inflammatory cytokines contribute to the production and secretion of IL-8 in inflamed joint diseases, such as RA [24–26]. Here, CXCL8 is linked to rheumatoid arthritis.