In addition, high GFAP levels in blood of patients prior to treatment are associated with epidermal growth factor receptor amplified (EGFRvIII) tumors within grade IV astrocytoma (Muller et al., 2014), with IDHwt tumors within grade III and IV astrocytoma (Kiviniemi et al., 2015) and with higher levels of Ki67 (cell division marker) expression in tumor cells (Kiviniemi et al., 2015). Here, EGFR is linked to astrocytoma (excluding glioblastoma).