Inflammatory cytokines are associated with osteoarthritis. Relative cytokine levels in serum and synovial fluid (SF) samples from patients with osteoarthritis (OA) or rheumatoid arthritis (RA) and in serum samples from healthy individuals (normal sera). Cytokine levels were measured with a multiplex bead-based immunoassay. Samples from individual patients are listed above the heatmap, and the individual cytokines are listed to the right of the heatmap. IL, interleukin; IFN, interferon; MIG, monokine induced by IFN-γ; IP-10, interferon gamma-induced protein 10; IL-1ra, interleukin-1 receptor antagonist; VEGF, vascular endothelial growth factor; GM-CSF, granulocyte macrophage colony-stimulating factor; FGF, fibroblast growth factor; MCP, monocyte chemotactic protein; IL-2Rα, interleukin-2 receptor α chain; HGF, hepatocyte growth factor; GROα, growth-regulated oncogene α; MIP-1, macrophage inflammatory protein; β-NGF, β nerve growth factor; SCF, stem cell factor; M-CSF, macrophage colony-stimulating factor; SCGF-β, stem cell growth factor β; LIF, leukemia inhibitory factor; SDF-1α, stromal cell-derived factor 1α; G-CSF, granulocyte colony-stimulating factor; CTACK, cutaneous T-cell attracting chemokine.