Meanwhile, five out of 17 proteins, named Cyclin-dependent kinase inhibitor p12, Cyclin-dependent kinase inhibitor 1, Antioxidant protein 2, Protein disulfide isomerase A2, C1-tetrahydrofolate synthase were down-regulated both in LC-developed HCC and CHB-developed HCC. The gene discussed is PRDX6; the disease is hepatocellular carcinoma.