TGFB1 and glioblastoma: TGFB1: GBM, induction 2.19-fold ± 0.09, p = 0.015; primary GBM cells, induction 4.33-fold ± 0.69, p < 0.001; NB, n = 9; GBM, n = 39; primary GBM cells, n = 8).