MMP2 and Hepatic fibrosis: CCl4 injection resulted in liver fibrosis with a more pronounced effect in Parkin-/- mice, as shown by the hepatic mRNA levels of markers for hepatic stellate cell (HSC) activation and fibrosis (Col1a1, Acta22, and Mmp2) (Fig. 1b) as well as Masson and Sirius red staining (Fig. 1c, d).