ENTPD3, also known as ectonucleoside triphosphate diphosphohydrolase 3, is an integral membrane glycoprotein with an extracellular active site. It contains 4 apyrase-conserved regions which is characteristic of NTPases. Recombinant human ENTPD3, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.