MMP9 and Hepatic fibrosis: The qPCR analyses of Collagen-1, alpha smooth muscle actin (α-SMA), transforming growth factor beta (TGF-β) and a tissue inhibitor of metalloproteinases (TIMP-1) confirmed the development and progression of liver fibrosis/cirrhosis as a result chronic DEN treatment, which was associated with a non-significant decrease in matrix metalloproteinase (MMP)2 and MMP9 expression (Figure 2b).