IFNA1 and severe acute respiratory syndrome: If IFN stimulates the upregulation of α-SNAP, this would partially explain why SARS-CoV-2 is more sensitive to type I IFN than SARS-CoV (29) because SARS-CoV has no furin cleavage motif in its S protein and upregulated α-SNAP has no antiviral effect in SARS-CoV infection.