ENTPD1 and cancer: CD39, or nucleoside triphosphate diphosphohydrolase-1 (NTPDase1), plays a pivotal role in modulating the tumor immune response.[35] CD39 facilitates the proliferation of Tregs by activating their receptors and enhances immunosuppression through increased expression of immunosuppressive receptors.[36] In the context of PC, CD39 is highly expressed in cancer-associated fibroblasts (CAFs)[37].