MMP1 and rheumatoid arthritis: In patients with OA, the immunoexpression levels of TNF-α, IL-1β, IL-7, MMP-1, MMP-2, and MMP-3 were significantly higher in patients with active rheumatoid arthritis (RA), whereas the immunoexpression levels of IL-1, IL-2, IL-4, IL-6, IL-15, IL-18, and MMP-3 were not statistically different.