MMP9 and rheumatoid arthritis: However, the mRNA expressions of MMP-2, MMP-3, MMP-8, and MMP-9 dropped significantly after 20-μM Tan IIA treatment, which suggested that Tan IIA significantly blocked upregulation in mRNA expression of MMP-2, MMP-3, MMP-8, and MMP-9 stimulated by TNF-α in RA-FLSs.