Fig. 2

CD39 expression in immune cells under different conditions. In normal peripheral blood cells, CD39 is primarily expressed on T regulatory cells (Tregs), myeloid cells, and B cells. However, in the tumor microenvironment (TME), CD39 expression is upregulated in most immune cell populations, including myeloid cells, Tregs, T cells, and NK cells. This increase in CD39 expression leads to the generation of an immunosuppressive microenvironment with high levels of adenosine, which can inhibit immune cell function and promote tumor growth