Anti-CD39 antibodies are used in antigen-specific immunodetection in biological samples. The target CD39 is a known alias name of the protein ectonucleoside triphosphate diphosphohydrolase 1, encoded by the ENTPD1 gene in humans. This 510-amino acid residue protein is known to be involved in cell adhesion, among other biological processes. It is localized to the membrane of the cell and features palmitoylated and glycosylated post-translational modifications. In terms of tissue expression, it is noted to be expressed primarily on activated lymphoid cells. CD39 is also used as a cellular marker for characterizing myeloid-derived suppressor cells. Other synonyms for CD39 include ATPDase and NTPDase-1.