SOX2 and glioblastoma: As mentioned earlier, the stem cell phenotype of GBM cells is a critical determinant of tumor progression and therapy resistance.14 Oct4 and Sox2 drive GBM cell transition to a stem-like tumor-propagating state characterized by enhanced stemness and resistance to standard-of-care treatments.15 To define events that contribute to therapy resistance downstream of Oct4 and Sox2 in GBM we performed RNA sequencing (RNA-seq) on patient-derived neurospheres (i.e. GBM1A and GBM1B) with and without transgenic co-expression of Oct4 and Sox2 (i.e. GBM1A-O/S and GBM1B-O/S) (supplementary data set 1).