EPAS1 and neoplasm: Eventually, hepatocellular carcinoma (HCC) cells express ectonucleoside triphosphate diphosphohydrolase 2 (ENTPD2) when hypoxia-driven HIF-1α (but not HIF-2α) is present, which facilitates the onset and progression of syngeneic Hepa1-6 HCC tumors in mice by increasing the infiltration of MDSC into the tumor mass [66].