SOX2 and central nervous system cancer: Figure 3D shows two examples of this assay performed using GBM 179 and GBM 193 samples (p = 0.8, Student t-Test). Next, we stained matched samples of primary patient GBM tumorspheres for markers associated with neural and glioma cancer stem cells which have previously shown to be enriched in primary glioblastoma samples (10, 15–17). Examples are shown in Figures 3E,F which display immunofluorescence-based detection of two neural stem markers—Sox2 and tubulin III (Tuj1) in matched specimens.