1. a Unidad de Investigación, IECSCYL-Hospital Universitario de Salamanca, Salamanca, Spain
2. b Neurosurgery Service, Hospital Universitario de Salamanca, Salamanca, Spain
3. c Neuropathology Service, Hospital da Universidade de Coimbra, Coimbra, Portugal
4. d Centro de Investigación del Cáncer, Cytometry General Service and Department of Medicine, University of Salamanca, Salamanca, Spain