ENTPD1 and neoplasm: On the other hand, autophagy has been known to prevent the upregulation of CD39 on tumor cells, an ecto-ATPase that converts extracellular immunostimulatory ATP into immunosuppressive adenosine diphosphate (ADP) and that recruits regulatory T cells (Tregs) in the TME [8], and we also already highlighted that tumor cells are able to finely tune the ATP/ADP levels [9].