The function of MMP-2, MMP-9, and MMP-13 are currently being researched more in the process of liver fibrosis regression, since they can encourage liver macrophages to degrade the ECM and reverse fibrotic lesions, while MMP-9 released by Kupffer cells can also cause hepatic stellate cell apoptosis (HSCs) (Baeck et al., 2012). The gene discussed is MMP9; the disease is Hepatic fibrosis.