NOS2 and neoplasm: The function of T cells is dependent on their interaction with tumour cells and other TME cells, thereby, the factors influencing its activation include (apart from metabolic factors) TGF-β, IL-10 and ROS (by TAMs); Arg1, iNOS and ROS (by MDSCs); PD-L1 or CD80 receptors expression (in tumour cells) [490].