Although the importance of numerous genes, including TP53, PTEN, EGFR, MDM2, CDKN2A and CDKN2B (4–6), during glioma progression has been proven, assays for individual genes/proteins or in combination with histological features are neither predictive of survival of glioma patients nor able to guide therapeutic decisions (7). Here, PTEN is linked to central nervous system cancer.