Patients with malignant glioma generally have a bad prognosis. To improve patients' situation new therapy options as well as new possibilities to determine prognosis and prediction more precisely are needed. One approach is the targeted activation of the immune system to recognize and eliminate tumor cells. Due to cerebral tumors the brain is no immune privileged organ anymore, so that immune cells may pass the haemato-encephalic barrier to attack tumor cells. This study aims to offer valuable clues about how the immune system is influenced by standard therapies (radiotherapy and chemotherapy). Just with the background knowledge of immune mechanisms and influencing factors by tumor therapy, an effective anti-tumor response can systematically be induced by modulating immune therapy. To analyze immunological changes, immunophenotyping by flow cytometry is performed with blood from patients with malignant gliomas during their therapy concluding chemoradiation and chemotherapy alone. Count, class and activation status of immune cells are detected by flow cytometry. Together with additional analysis methods, information about immunological mediators like cytokines, chemokines and danger signals can be received. For these purposes serum and plasma are generated from blood samples and stored for prospective questions. The explorative determined results may also help to discover new, immunological based, prognostic or predictive tumor markers.