One of the largest study (IDEAL study) in which more than 3,000 patients infected with genotype 1 HCV infection were randomized into three treatment arms of either PEG-IFN-α2b 1.0 μg/kg/wk, PEG-IFN-α2b 1.5 μg/kg/wk or PEG-IFN-α2a 180 μg/kg/wk [11]. The gene discussed is IFNA2; the disease is genotype.