Several CD39 inhibitors, including ARL67156 and POM-1, have shown efficacy in animal models of follicular lymphoma, sarcoma, or murine melanoma, resulting in a partial overcome of T-cell hypo-responsiveness to stimulation [121], increased therapeutic response to chemotherapeutic agents [122], or inhibition of tumor growth [123], respectively. The gene discussed is ENTPD1; the disease is sarcoma.