ENTPD1 and neoplasm: Although Treg also expresses high P2X7, the extracellular nucleotidases CD39 and CD73 also increase in parallel relative to P2X7, and they can degrade ATP into adenosine, which helps Treg to escape the cytotoxic effect of P2X7 and act as immunosuppression, helping tumor cells to immune evade (48).