As demonstrated in Fig. 2, after treatment of DOX for 24 h, the percentage of DOX-positive cells (Fig. 2a), as well as the medium intracellular DOX fluorescence intensity (Fig. 2b), were significantly lower in the EpCAM+–CD133+ subpopulation of cells compared to that in the tumor bulk (p < 0.01), indicating the greater capacity of EpCAM+–CD133+ Huh7 and PLC/PRF/5 cells in extruding DOX. The gene discussed is PROM1; the disease is neoplasm.