The etiologies associated with ALF have continued to change further over the years with an apparent decline in viral hepatitis, and a remarkable increase in acetaminophen toxicity to its current level of ~44-50% of cases. A further problem in studying ALF is that the number of cases of a specific etiology observed at any one institution are vanishingly small. The earliest goals of the ALF Study then were to more carefully define the etiologies of ALF on a national scale, and to finally allow in-depth study of specific ALF causes such as autoimmune ALF, viral hepatitis and Wilson disease (WD).