S1PR2 and biliary atresia: However, due to the limited understanding of disease pathology and lack of reliable early diagnostic markers, biliary atresia represents the primary indicator for pediatric liver transplantation and the most common cause of advanced cirrhosis.44 H19 plays crucial roles in cholangiocyte growth and cholestatic liver injury in biliary atresia via regulation of let-7/HMGA2 and S1PR2/SphK2 axes.