The protein fragments or peptides formed by telomerase degradation in tumor cells are expressed on the surface of tumor cells as tumor-associated antigens via the human leukocyte antigen (HLA) class I pathway, which in turn triggers antitumor cytotoxic T lymphocyte responses.390 CD4+ or CD8+ cytotoxic T lymphocytes can target telomerase-specific antigenic epitopes to kill tumor cells.1076 Current telomerase-based cancer immunotherapy mainly includes the hTERT vaccine and dendritic cell strategy. The gene discussed is CD4; the disease is neoplasm.