PDGFB and glioblastoma: In addition, similar results were observed in Nf1-silenced murine GBM (Nf1 mGBM) (model of human MES GBM); Nf1 expression was suppressed by shRNA compared with PDGFB-driven GBM (PDGFB mGBM) (model of human PN GBM) (Figure 2B, P < 0.05).