Liver biopsy showed moderately differentiated adenocarcinoma with necrosis involving the liver parenchyma, and immunohistochemistry for mismatch repair proteins indicated that the tumor was positive for MutL Homolog 1, MutS Homolog 2, MutS Homolog 6, and Protein Homolog 2. The gene discussed is MSH2; the disease is adenocarcinoma.