Furthermore, infection of A549 cells with Ad-NEU1-G68V encoding a catalytically dead NEU1 mutant also diminished PI3K–MUC1-CD association (Fig. 6A, lanes 4 versus 2), indicating that NEU1 catalytic activity was not required for NEU1-mediated disruption of PI3K–MUC1-CD association. This evidence concerns the gene NEU1 and infection.