Table 1.

Summary of HCC cancer stemness markers that have been validated by tumorigenicity assays.

CSC markers	Functions in liver cancer stem cells	Subcellular localisation	References
Well-established markers
CD13	Enhances side population, sphere formation, tumorigenicity, 5-FU and doxorubicin resistance; protects from ROS-induced DNA damage	Cell surface	14,15
CD24	Promotes cisplatin resistance, sphere formation, stemness gene expression, migration and invasion, tumorigenicity and STAT3 signalling to enhance Nanog expression; co-expression with CD133 promotes secondary tumour formation in vivo by inducing iNOS and Notch signalling	Cell surface	7,16
CD44	Promotes sorafenib resistance, sphere formation and tumorigenicity; helps maintain c-Met-induced stemness phenotypes	Cell surface	17,18
CD133	Promotes sphere formation, colony formation, stemness gene expression and tumorigenicity	Cell surface	10
EpCAM	Promotes sphere formation, invasion, 5-FU resistance, tumorigenicity and Wnt/β-catenin signalling; promotes EpCAM+ AFP+ hepatic stem-cell-like (HpSC) subtype; enhances SALL4 expression	Cell surface	6,12
Potential new markers
ICAM-1	Promotes sphere formation, tumorigenicity and lung metastases; forms a feed-forward loop with Nanog	Cell surface	26
LGR5	Promotes stemness gene expression, sphere formation, tumorigenicity, and sorafenib and cisplatin resistance; stimulates hepatocyte and bile duct regeneration upon liver damage; enhances Wnt/β-catenin signalling	Cell surface	27,29,31,32
MAEL	Promotes stemness gene expression, EMT, migration and invasion, cisplatin resistance and tumorigenicity	Cytoplasmic	29,31,32,36
Cripto-1	Promotes stemness gene expression, migration and invasion, sphere formation, sorafenib and cisplatin resistance and tumorigenicity; stabilises Dvl3 protein to promote Wnt/β-catenin signalling	Cytoplasmic	35,36