背景资料：Ectonucleotide pyrophosphatase/phosphodiesterase family member 7 (E-NPP 7) also known as alkaline sphingomyelin phosphodiesterase (Alk-SMase) or intestinal alkaline sphingomyelinase is an enzyme that in humans is encoded by the ENPP7 gene. Converts sphingomyelin to ceramide. Also has phospholipase C activity toward palmitoyl lyso-phosphocholine. Does not appear to have nucleotide pyrophosphatase activity. Inhibited in a dose dependent manner by ATP, imidazole, orthovanadate and zinc ion. Not inhibited by ADP, AMP and EDTA. Detected in the colon (at protein level). Expressed in the duodenum, jejunum and liver and at low levels in the ileum. Expression was very low in the esophagus, stomach and colon.