IFNA2 and chronic hepatitis C virus infection: Interferon-alpha (IFN-α) based antivirus therapy, regular IFN-α or pegylated interferon alfa (Peg-IFN-α), in combination with ribavirin or alone, is recognized as being a highly effective treatment for patients with chronic hepatitis C (CHC).This therapy results in a sustained virologic response (SVR) in 40–50% of patients with genotype 1, and around 80% in those infected with genotype 2 and 3 (3, 4).