In cancer patients, NK cells have been found to be altered in their anti-tumor functions, as a consequence of several TME-related factors (TGFβ, adenosine, PGE2), TME chemical conditions (acidity, abundance of ROS and lactate, hypoxia) and interactions with MDSCs, and in particular with PMN-MDSCs [6,33,34,35,36,37]. This evidence concerns the gene TGFB1 and neoplasm.