PTEN and oligodendroglioma: Second, we demonstrated the malignant features of GBM with the TERTp mutation based on clinicopathological characteristics, but patients with oligodendroglioma (the most benign diffuse glioma) also had the TERTp mutation.6 Third, it has been reported that PTEN, PI3K3A mutation and the expression of CD133 are associated with distant recurrence in patients with GBM.16,17,39,40 In the present study, there was no significant association between CD133 expression and the TERTp mutation, but PTEN deletion was significantly correlated with TERTp mutations and multifocal/distant lesions.