We performed western blotting to compare the levels of the PDK1 isoform in CD133/PROM1LOW versus CD133/PROM1HIGH patient-derived GBM cells and found that PDK1 was higher in CD133/PROM1HIGH, suggesting inhibition of pyruvate-dependent mitochondrial metabolism (Additional file 1: Figure 3B). The gene discussed is PDK1; the disease is glioblastoma.