EGFR and glioblastoma: In the TCGA-GBM dataset, while ERBB2-4 are not mutated in any of the four subtypes, there was notable copy number loss for ERBB2 in ME samples (23.4%) and ERBB3 in NE and PN samples (12.5% and 20.0%, respectively), suggesting that these receptors may play a more secondary role in GBM compared to EGFR.