CD8A and neoplasm: A plethora of mechanisms mediate the tumor-induced immunosuppression, including: changes in tumor surface antigens; release of immunosuppressive cytokines in the tumor microenvironment; expansion of T-helper 2 lymphocytes, T-regulatory (Treg) cells, myeloid derived suppressor cells and type 2-tumor associated macrophages, which favor the tumor growth and impair the activity of anti-tumor populations, such as T-helper 1 lymphocytes, CD8+ T-lymphocytes, type 1-tumor associated macrophages, natural killer cells [7].