POU5F1 and glioblastoma: Indeed, fenofibrate was previously reported to induce cell death in a PPARα-independent manner and to reduce the expression level of the stem-cell markers Oct4/CD133 in glioblastoma but the concentration in this experiment (25–100 μM) largely exceeded the clinically valid concentration (Cmax = 3 μg/mL: up to 10 μM) [44].