IFITM1 and infection: After 44 h, the level of HSV infection (MOI of 0.01) in IFITM1-expressing A549 cells was 36.6%, compared to 75.5% and 58.1% for IFITM2 and IFITM3, respectively, and 75.1% infection of control empty vector-transduced cells (Fig. 2B).