 Some paramyxoviruses, including SeV encode and synthesize neuraminidase (sialidase), which can remove sialic acid residues from the surface of malignant cells.Hemagglutinin-neuraminidase (HN) is a single protein that induces hemagglutination and possesses neuraminidase (sialidase) activity.Neuraminidase (NA), a subunit of the HN protein, binds to and cleaves sialic acid from the cell surface.