EGFR and glioblastoma: At the cut-off value of >5% of tumour cells with staining, 39% of patients were EGFR positive, and the expression of EGFR was restricted to only grade IV glioblastoma patients, and with no expression of EGFR in the tumour from astrocytoma patients, suggesting that EGFR expression is indicative of high grades of GBM [57].