In addition, in PAAD, antitumor effector immune cells, such as CD4+, CD8+ effector T lymphocytes, and NK cells, are reduced or nonfunctional (21), while immunosuppressive cells, such as tumor-associated macrophages (TAMs), regulatory T lymphocytes (Tregs), and myeloid suppressor cells (MDSCs), are functionally active and proliferate in large numbers (22). Here, CD8A is linked to neoplasm.