Co-staining with hepatocyte marker (HNF4α) or cholangiocyte marker (CK19) revealed that a proportion of LGR5 cells in the tumor express HNF4α or CK19 (Fig. 1g, h), suggesting that LGR5+ cells may give rise to both a HCC-like and a CC-like phenotype, the two main types of primary liver cancer. The gene discussed is HNF4A; the disease is cholangiocarcinoma.