We also subjected IAV-infected cells to immunofluorescence confocal microscopy at 24 h post-infection; this revealed that in the absence of p53, IFITM1 is abundant and localized to the perinuclear area and endosomal and lysosomal compartments, while in p53WT A549 cells, there was only weak labeling within endosomes and lysosomes (Figure 5D, left panel). This evidence concerns the gene IFITM1 and infection.