To offset this adverse host response, we engineered NDVs that expressed an anti-CD47 antibody or SIRPα-Fc immunoadhesin to pair direct oncolysis with local CD47 blockade to amplify SIRPα+ phagocytic-cell-mediated clearance of tumor cells and downstream antitumor immunity, as well as circumvent dose-related toxicities associated with systemic administration of CD47-blocking agents. The gene discussed is SIRPA; the disease is neoplasm.