Neoantigen is an immunogenic peptide formed by mutations in tumor cells and it is an ideal target for cancer immunotherapy. However, natural neoantigen is highly heterogeneous and difficult to identify. Here, we designed an artificial neoantigen with high immunogenicity, which could allow tumors to be recognized and killed by the immune system. We named this artificial neoantigen as Trojan horse antigen. In this project, we constructed a Trojan horse antigen expression system: pCDNA6.2-hTERT-HBsAg-EmGFP-miR-HBsAg and a specific activation system in tumor cells: PCDNA3.1(+) - Hulc-CeR-HBsAg. These two systems, which contain cancer-specific promoters and miRNA, form an AND gate for regulating the expression of the Trojan target antigen only in liver cancer cells, but not in normal cells. Then the human immune system will kill tumor cells by identifying Trojan horse antigen-specific.