In a knee lavage study of 23 non-RA patients with symptomatic meniscal tears and 15 normal subjects without knee pain, elevated levels of multiple SF cytokines were observed (IFN gamma, IL-2, IL-4, IL-6, IL-10, IL-13, MCP-1 and MIP-1-β) from injured knees compared to asymptomatic contralateral knees and from normal knees [15]. This evidence concerns the gene IL13 and rheumatoid arthritis.