CD44 and cancer: Inhibition with PFK158 or genetic knockdown of PFKFB3 showed reduced tumor formation in the CSC xenograft model with reduced expression of phospho-PFKFB3 S461 and total PFKFB3, and cancer stem cell markers including CD133, CD44, Aldh1, Sox2, and ABCG2 (Fig. 7a–f).