ADO is produced from the dismantling of mono- and dinucleotides (ATP and NAD+) and their byproducts (ADP, ADPR, AMP) by a set of ectoenzymes (CD39, CD38, CD203a, and CD73), of interest to both basic and clinical research because of their involvement in tumor biology and immune response. This evidence concerns the gene ENTPD1 and neoplasm.