4.1. Patients and Tumor Tissue

Clinical and Pathology data were collected from 39 patients, 33 primary GBM (14 males and 19 females) and 6 secondary GBM (5 males and 1 female). The study was approved by the Ethics Committee of La Laguna University (La Laguna, Canary Islands, Spain) and the Ethical Committee of Nuestra Señora de Candelaria University Hospital (HUNSC); Santa Cruz de Tenerife, Canary Islands, Spain (no. 198/2008, approved on 16 September 2008). All patients have been treated in the HUNSC between years 2007 and 2015 and provided informed consent for the diagnosis and research of tissue specimens prior to enrolment in the study. GBM samples were taken after initial surgery in the HUNSC before patients received radiation or chemotherapy. Paraffin-embedded tissue samples and corresponding clinical data were used ensuring patient’s anonymity.