Ectonucleoside triphosphate diphosphohydrolase (NTPDase) hydrolyzes nucleoside 5’-triphosphate to nucleoside 5’-phosphate and 2 phosphates. NTPDase can hydrolyze ATP and ADP. NTPDase has an important role in regulating neutrophil chemotaxis. NTPDase 1,2,3,8 are cell surface enzymes with catalytic sites facing extracellularly while other NTPDases act intracellularly. NTPDase require Ca+2 or Mg+2 for their activity. The NTPDases can be differentiated according to their substrate specificity, divalent cation usage and product formation.[1]