Moreover, they also observed that the CD133+CD44+ cells in HCC cell lines exhibited the advantage of expressing some stem cell-associated genes such as β-catenin and BMI-1 and were more resistant to multiple chemotherapeutics such as doxorubicin and vincristine on account of the upregulation of ATP-binding cassette (ABC) super family transporters (ABCB1, ABCC1, and ABCG2). Here, ABCG2 is linked to hepatocellular carcinoma.