In contrast to human influenza virus H1N1, A/tree sparrow/Henan/1/04(H5N1) infection in mammalian cells resulted in rapid IFN-β production during the early stage of infection, but in the late stage, it significantly inhibited the amplification of IFN-β production and showed the same pattern as the Indian isolate of pandemic (H1N1) 2009 influenza virus [32]. The gene discussed is IFNB1; the disease is infection.