YBX1 and glioblastoma: Based on this knowledge and combined with the observation that high YB-1 expression and/or its nuclear localization are closely associated with poor prognosis in GBM and other malignancies [29,30], we hypothesize that nuclear YB-1 protein expression due to activated PI3-K/AKT and the RAS/MAPK pathways is significantly elevated in brain CSC, and thus may be useful in ablating CSC by Ad-Delo3-RGD.