Although the abnormal activation of AKT has been thought to play a major role in resistance to apoptosis and chemotherapy in a large percentage of human glioblastomas 37, it has been proposed recently that under certain conditions the abnormal activation of the PI3K/AKT pathway in PTEN-deficient glioblastoma cells could represent a disadvantage for cell survival 43. This evidence concerns the gene PTEN and glioblastoma.