MMP9 and hepatocellular carcinoma: In the interstitial matrix between liver parenchymal cells of human liver tissues, TCs are heterogeneous, and alterations in their function are obvious, especially when liver fibrosis, liver tumors and inflammation occur, suggesting that TCs play an important role in the development of liver diseases.[52] In a study on hepatocellular carcinoma (HCC), the expression of matrix metalloproteinase-9 in TCs was found to promote the metastasis of HCC.