IDH1 and glioblastoma: Genes on the panel that are of potential relevance to GBM include IDH1, IDH2, BRAF, EGFR, PDGFRA, PIK3CA, PTEN, and TP53. In some circumstances, for example, the panel is employed if there is a suspicion for a possible BRAF mutation based on the presence of epithelioid morphological characteristics.