1) Determine the prevalence and viral genetic variability, including genotypes and mutations, in serum samples of HCC patients co-infected with HBV and HCV
2) Characterize viral genetic variability, including HBV genotypes, mutations and cccDNA levels, in tumor tissue samples of HCC patients with occult and overt chronic HBV infection
3) Study the role of pretreatment genetic variability of HBV and HCV (particularly genotype 6) in prediction of response to PEG-IFN-based therapy
4) Study the viral kinetics of HBV and HCV (particularly genotype 6) during PEG-IFN-based therapy for prediction and individualization of treatment