ENTPD1 and neoplasm: A potential correlation of elevated CD73 and CD39 expression with microregional hypoxia (which has been assessed by the expression of hypoxia surrogate marker GLUT-1 on tumor cells) was evaluated as a risk factor for survival of these patients since an immunologically less active tumor microenvironment (TME) might diminish the response to immunotherapy [31] as well as radiotherapy (RT).