IFNA1 and chronic hepatitis C virus infection: Several interleukin-28B (IL28B)-associated single nucleotide polymorphisms (SNPs), including CC genotype of rs12979860 and TT genotype of rs8099917, are associated with a higher response rate in Peg-IFN-based treatment for chronic hepatitis C. Whether the IL-28B SNPs could also predict Peg-IFN-based treatment response in CHB has been actively investigated.