Molecular characterization of the CSCs and non-CSC fraction. FACS-sorted 5000 CSCs and non-CSCs were used to purify RNA and synthesize cDNA. Gene expression level was determined relative to β-actin. (A) CD117 expression was used to evaluate the efficacy of cell sorting. (Top panel) CD117 expression was higher in the CSCs than in the non-CSCs. (Bottom panel) Tax gene expression was not detected in CSCs. (B) Notch1 and Bmi1 expression was down-regulated in CSCs. CD44 expression was up-regulated in CSCs. No difference was observed in the expression of the other genes, Rex1, Flt3, SCL/tal-1, N-cadherin, Oct-4, and Nanog in the CSCs and non-CSC fraction. *P < .05 (significant).