It is thus highly likely that RT-induced damage might also trigger release of adenosine, activation of CD73, or both, in the irradiated tumor microenvironment; hypoxia-induced or RT-induced increase in extracellular adenosine levels might then limit RT-induced immune enhancement and increase resistance to combined radioimmunotherapy by adenosine-mediated immunosuppression [42,72,244,295,333]. This evidence concerns the gene NT5E and neoplasm.