Further study in HeLa cells [12] has revealed that enhancers can improve hTERT promoter activity by 6~13 times, among which SV40-CMV dual enhancer/hTERT promoter has the highest activity, which is nearly 3-fold of CMV enhancer/hTERT promoter; two hTERTp regulated CD/TK fusion suicide gene driven by SV40/CMV dual enhancer has very high specificity and efficacy to tumor cells. This evidence concerns the gene TKT and neoplasm.