While the aberrant events that trigger CSC transformation in TMZ-treated glioblastomas are not entirely worked out, studies in which patient-derived GBM cell lines have been successfully reprogrammed into CSCs through forced expression of neural stem cell transcription factors (Oct4, Sox2, Nanog) lend credence to the notion of aberrant de-differentiation [38]. This evidence concerns the gene NANOG and glioblastoma.