Anatomical location and differentiation capability of hepatic progenitor cells. A. Schematic representation of the anatomical location of the hepatic progenitor cell (HPC) in the canal of Hering. Upon activation the normally quiescent HPCs will proliferate. Depending on the disease and the concurrent changes in microenvironment HPCs will differentiate into either hepatocytes or cholangiocytes. PV: portal vein; BD; bile duct; PA: portal artery; COH: canal of Hering; SD: space of Disse; BC: bile canaliculus; CV: central vein B. Immunofluorescent double staining of panCK (red) and HepPar-1 (green) with a nuclear counterstaining (DAPI, blue) of a liver section of canine chronic hepatitis. Differentiation into hepatocytes can be observed where the ductular reaction enters the parenchyma as the intermediate hepatocytes lose panCK immunoreactivity and become positive for HepPar-1 .