CD8A and neoplasm: During early neoplastic lesions, the infiltration of cytotoxic effector cells such as CD8+ T cells prevails; however, as cancer cells progressively grow, these cells are gradually outnumbered by immature cells of the innate immune system like tumor-associated macrophages (TAMs), type 2, and myeloid-derived suppressor cells (MDSCs) acquiring immunosuppressive phenotypes [15].