Since Stat1 and Stat2 were retained in the cytoplasm during infection with WT HPIV1 but not F170S HPIV1, we investigated whether retention might be due to physical interaction with the C proteins, as has been reported for SeV C proteins, and whether the C proteins interacted with both phosphorylated and unphosphorylated Stat proteins. The gene discussed is STAT1; the disease is infection.