As presented in Table 4, kallikrein-6 (KLK6), the matrix metallopeptidase (MMP) 3 and 13 and the cathepsins (CTS) D and E were predicted to be significantly increased, whereas meprin A subunit α (MEP1A) and CTSB were found to be decreased in their activities in HCC compared to non-HCC liver diseases (p < 0.05 in the Mann–Whitney U test). This evidence concerns the gene KLK6 and hepatocellular carcinoma.