EGFR and glioblastoma: Subsequently, studies have shown that oncogenes, such as EGFR, platelet-derived growth factor receptor alpha (PDGFRA), Erb-B2 receptor tyrosine kinase 2 (ERBB2), and KIT Proto-Oncogene (KIT), are located on ecDNA in glioblastoma and are amplified in large numbers, which plays a role in promoting cancer.