The function of ENTPD2 (ectonucleoside triphosphate diphosphohydrolase 2, ENSG00000054179) is as follows. Catalyzes the hydrolysis of nucleoside triphosphates (NTPs) and diphosphates (NDPs), with a marked preference for triphosphonucleosides over diphosphonucleosides (PubMed:10510450, PubMed:12888562, PubMed:16101300, PubMed:18404504). The enzyme sequentially removes phosphate groups in two successive steps, converting NTPs to nucleoside monophosphates (NMPs) via NDP intermediates (PubMed:10510450, PubMed:12888562, PubMed:16101300, PubMed:18404504). This activity contributes to the regulation of extracellular nucleotides levels (PubMed:10510450, PubMed:12888562, PubMed:16101300, PubMed:18404504). ATP hydrolysis is characterized by fast ADP accumulation and delayed AMP formation, reflecting limited ADP hydrolase activity (By similarity). Hydrolyzes ADP and UDP only to a marginal extent, and does not hydrolyze AMP (PubMed:10510450, PubMed:12888562, PubMed:16101300, PubMed:18404504). All nucleoside 5'- diphosphates are hydrolyzed at rates lower than those of their corresponding triphosphates (By similarity). {ECO:0000250|UniProtKB:O35795, ECO:0000269|PubMed:10510450, ECO:0000269|PubMed:12888562, ECO:0000269|PubMed:16101300, ECO:0000269|PubMed:18404504}. [Isoform gamma]: Catalytically inactive. . [Isoform Short]: Catalytically inactive. .