Earlier work noted similar EGFR-ligand levels for EGFR-amplified and non-EGFR-amplified GBMs.35 The clinical relevance of EGFR ligands was underlined since high ligand expression was associated with an improved prognosis in EGFR-amplified GBM.35 The same work also discovered that an increased ligand availability resulted in smaller tumors, decreased invasion, and improved survival in mice. This evidence concerns the gene EGFR and glioblastoma.