TNF and neoplasm: Based on these above background, we hypothesis that, by transfectting eukaryotic vector pcDNA3.1 (+) carrying suicide CD and TNF-α gene into laryngeal cancer cell-Hep-2, this method can combine the complementary advantage of each gene, thereby improve the efficacy of gene therapy, increase anti-tumor immune responses, reduce their toxicity, exert the synergic cytocidal effect of suicidal gene as well as cytokine gene on tumor cells.