EGFR and glioblastoma: There was no difference in OS between the treatment arms in the overall trial population; however, in the small number of patients assessed by biomarker subgroup analysis, there was a non-statistically significant trend towards increased PFS in afatinib-treated patients expressing the EGFR-variant III (EGFR-vIII) mutation, an EGFR variant frequently found in GBM [14].