VEGFA and glioblastoma: Vascular endothelial growth factor-A (VEGF-A) and glial fibrillary acidic protein (GFAP) were evaluated a priori due to BBB disruption in HGGs46,47 and bevacizumab treatment, and GFAP being a proposed GBM biomarker.48–50 Glial fibrillary acidic protein increased (14.45×) during progression through bevacizumab, consistent with radiographic resistance to the anti-VEGF-A antibody (Figure 6A).