EGFR and glioblastoma: These findings are relevant to glioblastoma not only because most glioblastomas have EGFR alteration but also because at least 60% of the glioblastomas have PI3K signaling pathway deregulation resulting from genetic alterations in the PTEN tumor suppressor gene on 10q23 at the level of loss of heterozygosity, mutation, and methylation [42].