Ectonucleotide pyrophosphatase/phosphodiesterase family member 6 (ENPP6), also known as Glycerophosphocholine choline phosphodiesterase ENPP6, is a choline-specific glycerophosphodiester phosphodiesterase []. It is bound to the plasma membrane through its C-terminal glycosylphosphatidylinositol (GPI) anchor []. ENPP6 hydrolyses choline-containing compounds such aslysophosphatidylcholine and glycerophosphorylcholine, and might be involved in choline metabolism.