(C) HEK293T cells stably transfected with empty pQCXIP, IFITM3 WT-FLAG, or the indicated mutants were challenged with IAV PR8 strain (MOI of 0.1), fixed at 18 hr post-infection, stained with an anti-nucleoprotein antibody, and assessed by flow cytometry. This evidence concerns the gene IFITM3 and infection.