IFNA1 and chronic hepatitis C virus infection: Treatment of chronic hepatitis C with PEG-IFN-α and ribavirin for 48 weeks resulted in SVR rates of 54–56%, compared to 40–50% after treatment with standard IFN-α and ribavirin (Fried et al, 2002; Manns et al, 2001; Zeuzem et al, 2000).