ENTPD1 and neoplasm: Moreover, by checking the total number of B cells expressing both CD39 and CD73, we observed an increase of the CD39/CD73 positive B cell population during tumor formation over time at the expense of CD39−/CD73− B cells (Figure S1), suggesting a role of the CD39+/CD73+ B cell population and the related adenosine mediated immunosuppressive pathway during tumorigenesis.