PDGFRA and glioblastoma: Although clearly frequently co-amplified, both KIT and VEGFR2 were less commonly overexpressed at the protein level in response to the increase in DNA copy number, in sharp contrast to PDGFRA. Despite this there were significant differences in glioblastoma phenotypes, with isolated KIT receptor-positive tumour cells corresponding with an increased oligodendroglial morphology and MGMT promoter methylation, an association not previously reported.