CD44 and cancer: The impact of CAR activation on the expression of these stem cell markers was even more prominent in the tumorspheres, where CITCO significantly reduced the expression of multiple cancer stem cell markers including CD44 and EpCAM (in the tumorspheres derived from all three cell lines), CD24, CD44, CD133 and EpCAM (in the tumorspheres derived from Huh-7 and PLC/PRF/5 cells) (Fig. 2E).