Table 2.

Known differences between small and large cholangiocytes.

Phenotype	Small cholangiocytes	Large cholangiocytes
Location	Smaller bile ducts	Larger bile ducts
Shape	Cuboidal	Columnar
Intracellular structures	High nucleus to cytoplasm ratio	Low nucleus to cytoplasm ratio
	Multilobulated nucleus, few mitochondria, abundant Golgi apparatus, minimal rough endoplasmic reticulum	Multilobulated nucleus, few mitochondria, abundant Golgi apparatus, more rough endoplasmic reticulum
Apical surface	Lysosomes and vesicles localized to the apical membrane, tight junctions between cells, coated pits, microvilli	Lysosomes and vesicles localized to the apical membrane, tight junctions between cells, coated pits, microvilli
Protein expression	Express lipase, α-amylase and trypsin	Express lipase, α-amylase and trypsin
	AE1 absent, AE2 present	AE1 absent, AE2 present
	CFTR absent	CFTR present
	CYP4502E1 absent	CYP4502E1 present
	Blood group antigens present (e.g., A, B, O, Lewis)	Blood group antigens absent
	Bcl-2 present	Bcl-2 absent
Response to injury	Resistant to liver injury	Susceptible to liver injury
	Can proliferate (e.g., behave as liver progenitor cells)

Abbreviations: AE2, anion exchanger 2; Bcl-2, B-cell lymphoma 2; CFTR, cystic fibrosis transmembrane conductance regulator.