VWF and glioblastoma: The morphological examination and the computerized morphometric analysis showed groups with vWF-FVIII positive glial neoplastic cells to be significantly higher only in GBM and not in astrocytoma II compared to background, suggesting that the activity of vWF-FVIII within these cells is linked to the malignancy of gliomas as well as their location near the vascular glomeruloid structures associated with endothelial cells (Nowacki and Tabaka, 2003[43]).