PIK3CA and glioblastoma: Specifically, we found mutations in genes that are strongly involved in GBM, i.e., EGFR (3’ UTR, intron, and downstream gene variants), PDGFRA (3’ UTR, intron and downstream and upstream gene variants), PIK3CA (intron and upstream gene variants), PIK3R1 (upstream and downstream gene variants), and TP53 (upstream gene, intron and downstream gene variants).