The increased NP in the cytosol of the IFITM3 cells likely arises in part from an increase in the local concentration of viruses because α-NP Western blots (after trypsinizing the cells to remove adherent NP) did not show substantial differences in internalized NP levels between cell lines for up to 90 min post infection (p.i., data not shown). The gene discussed is NPPA; the disease is infection.