The cellular TME components can be categorized into (i) pro-tumorigenic / immunosuppressive cells including pro-tumor M2-macrophages, myeloid-derived suppressor cells (MDSCs), and regulatory T (Treg) cells, and (ii) anti-tumorigenic immune effector cells, such as anti-tumor M1-macrophages, cytotoxic CD8+ T cells and natural killer (NK) cells (Duan et al., 2020; Zheng et al., 2017). Here, CD8A is linked to neoplasm.