During the process of tumorigenesis, tumor microenvironment (TME) tips the balance from immune surveillance to immune evasions as a consequence of the decrease in cytotoxic CD8+T and NK cells, increased immunosuppressive regulatory T cells (Tregs), exhausted CD8+T cells, and helper T lymphocyte type 2 (Th2) polarization. Here, CD8A is linked to neoplasm.