PKM and glioblastoma: Stem cell-like and non-stem-like patient-derived GBM tumor subpopulations were comprehensively screened for differences in the expression of enzymes involved in catalyzing the breakdown of glucose through the glycolytic pathway, including; the glucose transporter GLUT1/SLC2A1, phosphofructokinase (PFKP), aldolase A (ALDOA), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), enolase 1 (ENO1), and pyruvate kinase isoform M2 (PKM2) (Fig. 2a, b).