Previous array-based studies in which CN alterations are related to GEP have contributed to the identification of cancer associated genes relevant to GBM (e.g. MYCN, PIK3CA, CCND2, KRAS, CHD5, CXCL12, PTER, LRRN6C, ERRFI1 and TACC3, and at the same time they have confirmed the pathogenic role of other known genes (e.g. EGFR) [8], [22], [23], [24], [25], [26]. This evidence concerns the gene PIK3CA and glioblastoma.