We found that a serine protease uPA (urokinase-type plasminogen activator) and its receptor uPAR, and two matrix metallopeptidases MMP9 and MMP20, were downregulated upon SPINK6 expression in the HCC cells and result of gelatin zymography also showed that the biological activity of MMP9 was inhibited during the over-expression of SPINK6 (Supplementary Figure S6). This evidence concerns the gene PLAU and hepatocellular carcinoma.