ENPP2, Autotaxin or Extracellular lysophospholipase D, is a 863 amino acid secreted protein, which is detected in blood plasma (at protein level) (PubMed:12176993, PubMed:26371182). ENPP2 is Predominantly expressed in brain, placenta, ovary, and small intestine. ENPP2 is expressed in a number of carcinomas such as hepatocellular and prostate carcinoma, neuroblastoma and non-small-cell lung cancer. ENPP2 is expressed in body fluids such as plasma, cerebral spinal fluid (CSF), saliva, follicular and amniotic fluids. Biliary atresia patients had greater serum autotaxin and liver stiffness than controls. Serum autotaxin and liver stiffness were markedly elevated in Biliary atresia patients with jaundice compared to those without jaundice. Furthermore, serum autotaxin was correlated with liver stiffness and biochemical parameters in Biliary atresia. This kit is used to quality ENPP2 level in serum.