The Childhood Liver Disease Research Network (ChiLDReN) is a collaborative team of doctors, scientists, nurses, research coordinators, medical facilities, patient support organizations and the National Institutes of Health. The ChiLDReN Network has clinical sites and research laboratories in the U.S., Canada, and the United Kingdom. These sites are working together to improve the lives of children and families dealing with rare cholestatic liver diseases. The ChiLDReN Network combines the Biliary Atresia Research Consortium (BARC) and the Cholestatic Liver Disease Consortium (CLiC), as well as new studies on cystic fibrosis liver disease (CFLD). The ChiLDReN Network was developed to support the discovery of new diagnostics, etiologic, and treatment options for ChiLDReN with liver disease, and those who undergo liver transplantation. The Network also supports training for the next generation of investigators in rare, pediatric liver diseases. One of the primary goals of the Network is to provide a way for patients to join with doctors and researchers by participating in research studies. The greater the collaboration between doctors and patients and their families, the more we can learn about rare liver diseases. This important first step is necessary if we are to find new and better treatments. Infants, ChiLDReN, and young adults with cholestasis (blockage of bile flow from the liver) who receive their medical care at one of the participating ChiLDReN centers may be eligible to enroll in current ChiLDReN studies. Patients who receive their medical care at other clinical facilities may also be eligible for ChiLDReN studies if they are able to visit a ChiLDReN site for regular research visits.