ISG expression is not predictive of treatment response in patients infected with HCV g3. PBMCs were isolated from G3 infected patients pre-treatment and stimulated with IFN-α. qRT-PCR was used to quantify (A) endogenous and (B) IFN-α stimulated induction of ISGs. Gene expression was normalised to expression of RPS15 and expressed on a log scale. Data were analysed using Mann–Whitney U-tests.