ENG and hepatocellular carcinoma: Various in vitro cell lines, including those of normal hepatocytes [49], HCC cancer cells [16,50], as well as undifferentiated and differentiated adult-derived human liver stem/progenitor cells [49,51], human adipose-derived stem cells [52], and hepatic perivascular mesenchymal stem cells [48,53] are also characterised by endoglin expression of varying levels.