The study enrolled fifteen patients with malignant glioma and six with primitive neuroectodermal tumors (PNET), who received high-dose intravenous cyclophosphamide for two consecutive days (1.8–2.25 g/m2 per day; total dose 3.6–4.5 g/m2), followed by GM-CSF (5 mg/kg per day) from day 3 to day 11 or until the granulocyte count reached at least 1.5 × 109/L. Here, CSF2 is linked to primitive neuroectodermal tumor.