Tumor-infiltrating T lymphocytes play a pivotal role in tumor immunity (32–34), and they exert complex immunomodulatory effects through different subpopulations such as CD4+ T cells and CD8+ T cells (35, 36), as well as anti-tumor pro-inflammatory T cells, immunosuppressive Th2 cells, Th17 cells, and regulatory T cells. The gene discussed is CD8A; the disease is neoplasm.