Both IL-1β-induced synovitis and intra-articular lavage resulted in transient joint inflammation with elevations in synovial fluid TP, WBC count, and PGE2; however, increases in TNF-α and inflammatory chemokines CCL2, CCL3, CCL5, and CCL11 were predominantly restricted to synovitis joints only. The gene discussed is IL1B; the disease is synovitis.