Phillips classification of GBM based on transcription profiling provides the following subtypes of GBM: proneural with normal EGFR and PTEN expression, normal EGFR locus and no chromosomal alterations; proliferative with loss of PTEN expression, normal or amplified EGFR locus, and either gain of chromosome 7 or loss of chromosome 10; mesenchymal with loss of PTEN expression, normal or amplified EGFR locus [2,17]. Here, PTEN is linked to glioblastoma.