SOX2 and glioblastoma: This was further validated by immunoblot analysis that confirmed CD133/PROM1HIGH patient-derived GBM cells have higher overall protein expression of BMI1 (p < 0.01), SOX2 (p < 0.01), and Nestin (p < 0.0001) as well as mRNA levels of Nestin/NES (p < 0.001) and SOX2 (p < 0.05) compared to CD133/PROM1LOW cells (Fig. 1c; Additional file 1: Figure 1B).