MMP9 and rheumatoid arthritis: SOE also reduced the expression of MMP9 while increased the expression of MMP2 in IL-1β–induced SW982 cells (Figure 7A), Xue et al. reported that endogenous MMP-2 or MMP-9 contribute to RA synovial fibroblast survival, proliferation, migration, and invasion, with MMP-9 having more potent effects.