Ectonucleotide pyrophosphatase/phosphodiesterase family member 1 (ENPP1) possesses alkaline phosphodiesterase I and nucleotide pyrophosphatase activities []. ENPP1 hydrolyses extracellular nucleotide triphosphates to produce pyrophosphate and regulates bone mineralization, soft tissue calcification, and insulin signalling [, , ].Mutations in the ENPP1 gene cause several pathological calcification syndromes, such as idiopathic infantile arterial calcification (IIAC) []and ossification of the posterior longitudinal ligament of the spine (OPLL) [].
