The liver has many functions, including building proteins and other substances for the body to use, drug metabolism, and energy storage. The liver also removes waste products and toxins from the blood. Liver disease causes these crucial functions to fail. When liver failure is too severe to respond to medications, liver transplantation may be an option. Because transplantation is a major surgical procedure and there is a shortage of available donor organs, not every person with liver failure can receive a transplant. At each transplant center, a multidisciplinary team reviews and selects patients who are then placed on a waiting list for a suitable donor organ. These donor organs are allocated based on need (the most severely ill persons are considered first) and compatibility of donor and recipient. The January 18, 2012, issue of JAMA includes an article about liver transplantation in children. This Patient Page is based on one previously published in the May 10, 2006, issue of JAMA.