EGFR and glioblastoma: Of all 34 gliomas, we found 7 gliomas (21%) with EGFR amplification: While we did not find EGFR amplification in low-grade gliomas (0%)—i.e., CNS WHO Grade 1 (0%) and CNS WHO Grade 2 (0%)—25% of high-grade astrocytomas and glioblastomas CNS WHO Grade 4 gliomas showed EGFR amplification (Figure 2a–c).