Clinical studies have shown (19): when the body’s immune function is enhanced, the proportion of CD8+ T lymphocytes in immune cell subsets increases significantly; while CD8+ T lymphocytes are effector T lymphocytes, which are involved in the body’s immune response.During this process, it plays the role of killing antigens, including cancer antigens, which can reflect the cellular immune status of the body (20, 21). The gene discussed is CD8A; the disease is cancer.