Alpha-fetoprotein (AFP) is a 65 kDa glycoprotein found in the serum of the mammalian fetal liver, yolk sac, and GI tract. While AFP expression in adult cells is low, it is aberrantly expressed in adult liver cancer cells (1,2). The tumor suppressor gene p53 and β-catenin are both involved in the regulation of AFP expression. In normal adult cells, p53 binds to the repressor region of the AFP gene, thereby blocking transcription. Mutations in both p53 and β-catenin are associated with aberrant expression of AFP. Elevated serum levels are predictive of hepatocellular carcinoma (3).