CD39L1 protein (ENTPD2 or NTPDase2) is a member of the ecto-nucleoside triphosphate diphosphohydrolase family which the main role is termination of purinergic signaling. CD39L1 gene encodes a precursor protein with 495 amino acid residues which generates a 437 amino acid residues mature protein after processing. It is an ecto-nucleotidase that found on the surface of vascular adventitial cells and accessory vascular cells. CD39L1 is a Ca2+- and Mg2+-dependent enzyme that activates platelets by preferentially converting ATP to ADP. CD39L1 plays a role in regulating thrombosis and inflammation which is considered to be a therapeutic target for thromboregulation and the treatment of vascular inflammation. Alternative splicing of CD39L1 gene results in multiple transcript variants.