On the other hand, virus infection of tumour cells can induce the production of cytokines such as IFN-α, IFN-β, TNF-α and IL-1; thus, a large number of immune cells outside the tumour are induced to infiltrate into the tumour, where the activated nonspecific immune cells can kill and devour infected tumour cells that have not yet lysed or are resistant to viral oncolysis 53. This evidence concerns the gene TNF and neoplasm.