The liver plays an important role in the disposition of copper. Most dietary copper passes through the liver where it can be used for protein and energy production or excreted through the biliary route. Because copper is a prooxidant, its intracellular handling is tightly managed. In Wilson disease, in which synthesis of ceruloplasmin and biliary excretion of copper are defective, copper accumulates in the liver and leads to progressive liver damage. The features of hepatic Wilson disease are highly variable. The spectrum of liver disease includes mild inflammation, fatty liver, an autoimmune disorder, and cirrhosis. Wilson disease thus resembles drug hepatotoxicity, and indeed it can be regarded as a prototypic example of endogenous hepatotoxicity. Biomarkers developed for detecting drug hepatotoxicity may be relevant to Wilson disease. Biomarkers developed through metalloproteomics, which for copper seeks to define a set of proteins that have copper-binding capacity, or through genomic studies may also be relevant to Wilson disease and other disorders of copper handling, whether copper is deficient or overloaded.