Transfection of the eight candidate miRNAs individually revealed that miRNAs miR-196, miR-296, miR-351, miR-431 and miR-448 were indeed able to substantially attenuate viral replication, whereas miRNAs miR-1, miR-30 and miR-128 were without effect (Fig. 2a). Transfection of a mixture of the five functional miRNA-mimics yielded a >80% reduction in viral RNA load. As IFNbeta induces miRNAs miR-196, miR-296, miR-351, miR-431 and miR-448 but downregulates miR-122, we decided to imitate this cellular response by transfecting the mix of miRNA-mimics in combination with anti-miR-122.