Besides adult patients, Kremer et al. also described significantly increased ATX levels in pediatric CCLD patients with pruritus (Alagille syndrome, extrahepatic biliary atresia, neonatal sclerosing cholangitis, PFIC) compared to children with BA synthesis defects, in which pruritus is typically not observed and tBA are low (26). The gene discussed is ENPP2; the disease is Pruritus.