CD39 (also known as ectonucleoside triphosphate diphosphohydrolase-1, ENTPD1ase) and CD73 (also known as ecto-5′-nucleotidase, Ecto5′NTase) are ectonucleotidases expressed on the surface of tumor cells and immune cells for the metabolism of nucleotides. This evidence concerns the gene ENTPD1 and neoplasm.