ENTPD1 and cancer: Ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1/CD39) is not the only ATP-degrading enzyme that is expressed by tumor cells; for example, nucleoside triphosphatase, cancer-related (NTPCR) is also expressed by some tumors which can bind to extracellular ATP and then convert it to adenosine (Moesta et al., 2020).