A. Immunofluorescence of SATB2 (green) and the GSC marker SOX2 or OLIG2 (red) on frozen tissue sections of human GBM surgical specimens. SATB2 is preferentially expressed by GSCs in human GBMs. Scale bar, 25 μm. B. Quantification of the fraction of SATB2+ cells in SOX2+ or OLIG2+ cells in human GBMs. More than 90% SOX2+ or OLIG2+ cells showed SATB2 staining. n=3 GBMs. 