CD8A and neoplasm: Specifically, under hypoxia stress, tumor cells secrete interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) to drive M2-TAM polarization 59, and they upregulate the expression of CD39 and CD73 to generate adenosine as a toxic metabolite, which diminishes CD8+ T cell cytotoxicity 60.