Fig. 1

Pathogenesis and structure of MMP9. (a) The multifaceted role of MMP9 in the pathogenesis of RA. MMP9 contributes to key pathological processes, including ECM and cartilage degradation, tissue invasion and breakdown, immune infiltration, inflammation, and angiogenesis, which are hallmarks of RA (b) Structural representation of MMP9, highlighting its functional domains.