MYOM2 and neoplasm: Structural studies of NDV viral proteins revealed various levels of assembly potential: NP monomers forming helical clam-shaped nucleocapsid structures and M proteins assembling in host cell plasma membranes into hollow helical oligomers; HN proteins on infected tumor cell membranes forming dimers and tetramers capable of interacting with NK cells and T cells, thereby cross-linking activating receptors; and molecular interactions between HN and F proteins, leading to fusion promotion activity of importance for virus cell entry, syncytium formation, and virus spread.