There was a trend suggesting that the IFN-β and RANTES gene expressions were more induced by influenza H5N1 virus (483/97) at 24 hours post-infection when compared to that in influenza H1N1 (54/98) and mouse adaptive H1N1 (WSN/33) viruses infected mouse macrophages, but statistical significance was not achieved (Figure 5B and 5D). This evidence concerns the gene IFNB1 and infection.