At the same time, OVs therapy can regulate the expression of immune inhibitory factors, such as inducing tumor cells to produce interferon and other cytokines to down-regulate PD-L1 expression and the inhibitory capacity of CTLA-4, enhancing the recognition and killing of tumor cells by immune cells, and improving the sensitivity of lung cancer to OVs therapy (39, 55). This evidence concerns the gene CTLA4 and neoplasm.