Rare subpopulations of poorly differentiated neoplastic cells, visually quantified at less than 1% of the neoplasm, had immunoreactivity for cytokeratin 19 (KRT19), a marker for biliary cancer or small-cell undifferentiated type hepatoblastoma38, as well as non-neoplastic, entrapped bile ducts. The gene discussed is KRT19; the disease is neoplasm.