IFNB1 and infection: Total nuclear STAT1 levels in response to IFN-β treatment were also affected by hMPV infection, as cells receiving both treatments did not exhibit an amount of STAT1 equivalent to additive levels induced by hMPV infection and IFN-β stimulation alone (middle panel: lane 4 vs lane 3+ lane 2, lane 8 vs lane 6+ lane 7).