CDKN2A and glioblastoma: Two different types of cell lines were selected for this study: non-stem cancer cells that contain a small CSC subpopulation (PANC1, human pancreatic carcinoma; SKOV3, human ovary adenocarcinoma; and GL261, murine glioma) [41–43] and pure glioblastoma-derived neural stem cells (GNS; patient-derived G7 human and engineered Ink4a/ARF, EGFRvIII overexpressed IENS murine) [31].