NT5E and neoplasm: The hypoxia-induced, hypoxia-inducible factor-1 alpha (HIF-1α)-dependent expression of CD73 and ADORAs in tumor cells and host cells [219,320,335,336,337] make CD73 and adenosine promising targets particularly for tumors with pronounced hypoxia, high HIF-1α–expression, or both, (e.g., [244,295]).