Liver disease is the fourth leading cause of death among middle aged adults in the United States. Loss of liver function can be caused by several factors, including genetic mutations, infections with hepatitis viruses, by excessive alcohol consumption, or chronic use of some prescription drugs. When liver function goes awry it can result in a wide variety of disorders including diabetes and atherosclerosis and in many cases is fatal.  Stephen A. Duncan, from Medical College of Wisconsin (USA), and colleagues reprogrammed human skin cells into stem-cell like state, then coaxed the intermediate cells to become liver cells.  The team found that the liver cells produced from human skin cells performed many of the activities associated with healthy adult liver function, and that the cells could be injected into mouse livers, where they integrated and were capable of making human liver proteins.  Noting that: “It is possible that in the future a small piece of skin from a patient with loss of liver function could be used to produce healthy liver cells, replacing the diseased liver with normal tissue,” the Medical College of Wisconsin posits that “the reprogrammed skin cells could be used to investigate and potentially treat metabolic liver disease.”