NES and neoplasm: Unlike orthotopic tumors developed from established GB cell lines, the COMI primary GIC-driven orthotopic GB faithfully recapitulates the growing properties of the clinical tumor including a relatively slow growth rate which leads animals to death in around 100 days (Fig. 2b), infiltration of the normal brain parenchyma as observed after H/E staining (Fig. 2a bottom and top) and a massive positive component for the stem cell marker nestin, as determined by immunohistochemistry with a specific antibody (Fig. 2a left).