MMP9 and metabolic dysfunction-associated steatohepatitis: Particularly in patients with non-alcoholic steatohepatitis, serum matrix metalloproteinase-9 (MMP-9) levels were significantly higher than those in the control group (12.6 ± 6.5 vs. 8.1 ± 3.5 μg/L, p < 0.01) (12).