Although the quantity of mRNA for HA (hemagglutinin) relative to that of mRNA for glyceraldehyde-3-phosphate dehydrogenase in influenza virus-infected MDCK cells decreased to less than 10% in the presence of the anti-influenza agent ribavirin (5 μg/mL), it never decreased in the presence of 100 μg/mL of PWE (data not shown). This evidence concerns the gene GAPDH and influenza.