What was noteworthy was that ENTPD1/CD39 (ectonucleoside triphosphate diphosphohydrolase 1) encodes a plasma membrane protein that hydrolyzes high-energy phosphate bonds, and some regulatory T cells with ENTPD1/CD39 overexpression played an important role in the breast cancer microenvironment (Gourdin et al., 2018). This evidence concerns the gene ENTPD1 and breast cancer.