KRT7 and neoplasm: Since cytokeratin 7 (CK7) and cytokeratin 19 (CK19) is generally expressed in bile ductal epithelium35,36, we therefore carried out IHC staining of CK7 and CK9 in liver tissue/tumor sections derived from the mice implanted with either WBCtrl or WBBMI1 cells, indicating the presence of CK7 and CK19 positive bile duct epithelial fragments on the surface of the tumor thrombi in WBBMI1 implanted mice with jaundice (Fig. 3e).