A large in-frame deletion in the extracellular domain of EGFR spanning exons 2–7 which encode domains I and II, known as EGFRvIII, is the most common and well-studied GBM-associated EGFR mutant [32], although less common point mutations in the extracellular domain have also been identified in GBM [31,33,34]. Here, EGFR is linked to glioblastoma.