The present invention provides an anti-influenza virus agent that targets biomolecules of host cells including human cells and a method of screening a candidate molecule for the anti-influenza virus agent. That is, the present invention is an anti-influenza virus agent that has an effect of suppressing expression or a function of a gene that encodes a protein having an effect of suppressing incorporation of an influenza virus vRNA or an NP protein into influenza virus-like particles in host cells and the gene is at least one selected from the group including JAK1 gene and the like.
