In hepatocellular carcinoma (HCC), low PPARγ expression was correlated with more advanced TNM (tumor, node, metastasis) stages [335], and PPARγ activation decreased the invasive and metastatic potential of cancer cells in vitro and in vivo through the downregulation of MMP9 and 13, and the upregulation of the extracellular matrix-regulator tissue inhibitors of metalloproteinase (TIMP) 3, E-cadherin, and spleen tyrosine kinase [336]. This evidence concerns the gene MMP9 and hepatocellular carcinoma.