Instituto Gulbenkian de Ciência, Oeiras, Portugal, Department of Biology, Humboldt-Universität zu Berlin, Berlin Germany and Research Center ImmunoSciences, Charité - Universitätsmedizin Berlin, Berlin, Germany.|Tumorbiological Laboratory, Neurosurgical Department, Ludwig-Maximilians-University Munich, Klinikum Grosshadern, Munich, Germany.|Tumorbiological Laboratory, Neurosurgical Department, Ludwig-Maximilians-University Munich, Klinikum Grosshadern, Munich, Germany.|Department of Biology, Humboldt-Universität zu Berlin, Berlin Germany and Research Center ImmunoSciences, Charité - Universitätsmedizin Berlin, Berlin, Germany.|Instituto Gulbenkian de Ciência, Oeiras, Portugal.