EGFR and glioblastoma: EGFR activating mutations in the tyrosine kinase domain leading to the ligand-independent activation of EGFR are frequently detected in non-small cell lung cancer (NSCLC) and glioblastoma but are rarely found in other tumor types (7–11), providing a possible foundation for the tumor type-specific responses to EGFR-targeted therapies and immunotherapies.