As for the regulation of Ado production, it is plausible that enhanced expression of CD39 and(or) of CD73 by T cells (as well as on tissue cells), contributes to generation of Ado in tissues of tumor and chronic infections, and thus the activation of A2A/A2B signaling through paracrine and/or autocrine mechanisms is responsible for inducing dysfunction in T cells. Here, NT5E is linked to neoplasm.