The isolated serum exosome analysis from biliary atresia patients revealed elevated lncH19, high mobility group AT-Hook 2 (HMGA2) and sphingosine-1-phosphate receptor 2 (S1PR2) compared to healthy controls, further implicating that hepatic fibrosis in biliary atresia could be paracrine in nature. Here, S1PR2 is linked to biliary atresia.