MDM2 and central nervous system cancer: In the meantime, our current results suggest that, in order to fully appreciate their therapeutic potential, MDM2 inhibitors may need to be used in the treatment of glioblastoma patients with a minimal residual tumor burden, whose survival is most likely to be dependent on tumor recurrence initiated by glioma stem cells instead of on the growth of residual tumors driven by the proliferation of non-stem tumor cells.