MMP9 and Hepatic fibrosis: Among the studied MMPs we focused our attention on MMP-2 and MMP-9 for two different reasons: (i) they were the highest expressed MMPs among those analyzed; (ii) in the family of MMPs, MMP-2 and MMP-9 are particularly important for the development of liver fibrosis since they degrade type IV collagen (basal membrane) and therefore are involved in the early steps of tissue remodeling that characterizes chronic liver disease [21,22].