IFNA1 and chronic hepatitis C virus infection: To clarify the role of rs12979860 and rs8099917 alleles, which were researched the most of IL28B, in treatment response of patients with chronic hepatitis C (CHC) to PEG-IFN/RBV, we carried out a meta-analysis of the available cohort studies of the association between the SNP of IL28B and the SVR of patients with CHC treated with PEG-IFN/RBV.