To evaluate the role of AMPK in regulating synovial inflammation, RA FLSs were treated with the AMPK agonist AICAR or inhibitor Compound C. Treatment with AICAR alone reduced the expression of IL-1β, IL-6, IL-8, and MMP-9 in TNFα-induced RA FLSs (Figure 4A), and Compound C had opposite effects. The gene discussed is MMP9; the disease is rheumatoid arthritis.