MMP9 and rheumatoid arthritis: As shown in Figure 3C, the mRNA expression of MMP-2, MMP-3, MMP-8, and MMP-9 were very less and almost undetectable after DIM(25 and 50 μM) treatment, which indicated DIM profoundly inhibited increase in mRNA expression of MMP-2, MMP-3, MMP-8, and MMP-9 induced by TNF-α in RA-FLSs.