While it is unclear if CK19 and Prom1 expressing cells are progenitor cell derived (Govaere and Roskams, 2015[14]), or dedifferentiated hepatocytes (Mu et al., 2015[27]), recent studies have shown that increased CK19 and Prom1 expression in HCC is related to prognosis (Song et al., 2008[33]; Kim et al., 2011[20]; Govaere et al., 2015[14]) and recurrence (Song et al., 2008[33]; Zeng et al., 2012[41]). This evidence concerns the gene PROM1 and hepatocellular carcinoma.