All enrolled subjects were genotyped for the SNPs of the SCARB1 gene and IL28B gene. All their blood specimens were collected into EDTA tubes. Human genomic DNA was extracted by standard protocols with blood RBC lysis, cell lysis, DNA binding, wash and elution. Extracted DNA normalized to 50 ng/µl was obtained. DNA quality was assessed by calculating the absorbance ratio OD260 nm/280 nm using NanoDrop model ND-1000 (Thermo Scientific, Wilmington, DE, USA). The SNP was genotyped by using the ABI TaqMan allelic discrimination kit and the ABI7900HT Sequence Detection System (Applied Biosystems, Foster City, CA, USA)