The previous study showed that the expression of antiviral effector molecules protein kinase R (PKR), 2′-5′-ologoadenylate synthetase (OAS), and Mx, as induced by Type 1 interferons, correlates with the susceptibility to NDV infection in both primary macrophages and macrophage-derived tumor cells (e.g., RAW cells) as these molecules inhibit critical steps during RNA translation and/or assembly of virus particles in viral replication [21]. Here, MX1 is linked to neoplasm.