DESCRIPTION (provided by applicant): Pediatric liver disease is rare but can lead to other morbidities, organ transplantation, or even death. The Childhood Liver Disease Research Network (ChiLDReN) is a collaborative network dedicated to research endeavors related to eight pediatric liver diseases, namely biliary atresia (BA); Alagille syndrome (ALGS); alpha-1-antitrypsin deficiency; progressive familial intrahepatic cholestasis (PFIC); bile acid synthesis defects; mitochondrial hepatopathies; idiopathic neonatal hepatitis; and cystic fibrosis liver disease. ChiLDReN aims to promote clinical and translational research on pediatric liver diseases in hopes of elucidating the pathogenesis and natural history, and developing means of treatment and clinical management. The Network will continue to build its robust biorepository of plasma, serum, urine, DNA, and hepatobiliary tissue specimens for use in future studies and analyses. It will also continue to compile already considerable datasets on demographic, medical history, and neurocognitive characteristics of pediatric liver disease. The Network has also recently initiated a clinical trial to address key gaps in the early management of children with biliary atresia, and is on the brink of initiating several other trials, which will facilitate treatment options for children with rare liver disease. Our site aims to contribute to the goals of ChiLDReN by ensuring continued and future availability of patients for observational and interventional Network protocols. We will also continue to the intellectual needs of the Network by providing committee leadership within the consortium, actively participating in data analysis and manuscript development, and developing novel studies and protocols. To this effect, we propose a novel and exciting protocol to differentiate cholangiocytes from induced pluripotent cells, and to apply this technology to model several biliary diseases of direct relevance to the Network. Through the continuation of its longitudinal observational and interventional studies, ChiLDReN aims to discover new diagnostics, etiologies, and treatment options for children with rare liver disease and those who undergo liver transplantation. The findings from the studies and analyses conducted by ChiLDReN will ultimately help improve outcomes and quality of life for North American children who suffer from liver disease.