 Since the hemagglutinin-neuraminidase proteins of the SeV and NDV viruses are highly homologous, it is likely that the HN protein of the SeV virus can activate both CTL and natural killers cell responses.Most likely neuraminidase removal of sialic acid from the surface of malignant cells contributes to this effects.UV-inactivated SeV can cause dendritic cells (DCs) to maturate and to infiltrate a tumor, and "ex vivo" infection of DCs with recombinant SeV induces maturation and activation of DCs within 60 minutes.