 "This hypothesis is based on two observations.First, the functional hemagglutinin-neuraminidase protein of the oncolytic Newcastle disease virus (NDV), which is a relative of SeV, has been shown to enhance the tumor-specific cytotoxic response of CD8+ T-cells and to increase the activity of CD4+ T-helper cells.Second, UV-inactivated NDV, which is can not replicate, promotes anti-tumor CTL response as well as does intact NDV, which can replicate.