Figure 2: Table showing the anti-interferon activity of the NS1 protein of human influenza viruses and the mortality of human influenza viruses during pandemic. 1918PV and 2009PV are able to inhibit pre-transcriptional IFN-α production. H2N2, H3N2 and 1918PV are able to inhibit post-transcriptional maturation and nuclear export of host interferon-related mRNAs (IFN-α/β) via optimal binding to the human 30-kDa subunit of cleavage and polyadenylation specificity factor (CPSF30).