APP and Alzheimer disease: APP has been mostly studied for its role in neurodegenerative diseases: beta amyloid plaques are associated with neuronal cell death in Alzheimer’s Disease [42] but a recent study also suggests it may have an antiviral role, based on observations of decreased influenza A replication (H1N1 and H3N2) in cells treated with beta amyloid [43], consistent with the increase in viral titer observed in this study.