MMP2 and rheumatoid arthritis: For wound healing and transwell assays of migration and invasion of primary RA-FLS, the combination of artesunate and MTX (2.5–5 nM) showed similar inhibitory effects on migration and invasion as well as MMP-2 and MMP-9 suppression when compared with MTX (10 nM) alone, while the combination of artesunate and higher concentrations of MTX (7.5–10 nM) had significantly stronger inhibitory effect on migration and invasion than MTX (10 nM) alone (Fig. 4).