Our studies showed, for the first time to the best of the authors' knowledge, that miR-124 and miR-137: (1) are expressed at significantly lower levels in GBM tumors relative to non-neoplastic brain tissue; (2) are up-regulated during neuronal differentiation of adult mNSCs induced by growth factor withdrawal; (3) promote neuronal-like differentiation of growth-factor-deprived mNSCs, mOSCs and hGSCs; (4) promote G0/G1 cell cycle arrest in GBM cells and growth-factor-deprived hGSCs; (5) inhibit expression of CDK6 mRNA, CDK6 protein and phosphorylated RB in GBM cells. This evidence concerns the gene RB1 and glioblastoma.