 Therefore, the ability of SeV sialidase (NA) to remove sialic acid from the surface of malignant cells most likely helps to ensure the availability of tumor antigens for recognition by cytotoxic T lymphocytes.Experiments with UV-inactivated SeV showed that NK cells are important in virus-mediated inhibition of tumor growth.This was shown in a mouse model of renal cancer, in which the anti-tumor effect of SeV was suppressed by reducing the number of NK cells by co-injection of specific antibodies.