Apart from producing cytokines, different subsets of CD4+ T cell has been identified, including cytotoxic CD4+ T cells, which possess cytotoxic programs and can directly kill cancer cells [17].CD8+ T cells are cytotoxic and suppressive T cells that are involved in the maturation and positive selection of restrictive cytotoxic T lymphocyte for major histocompatibility complex-I [18]. Here, CD8A is linked to cancer.