MMP2 and hepatocellular carcinoma: MMP-9 and MMP-2 (also called gelatinases) are two of the most extensively studied members of the MMPs family [29], and over-expression of MMP-9 and MMP-2 in HCC can contribute to a higher Tumor-Node-Metastasis (TNM) stage by promoting the tumor cells to undergo metastasis as well as invasion and can also cause poor differentiation and overall poor prognosis.