NF1 and glioblastoma: Validation of a subset of these genes (CACNA1G, CALD1,FGFR1, MDM2, NF1, PECAM1 and TNC) by semi-quantitative RT-PCR confirmed GBM-specific splicing for four of seven (~60%) reported splicing events: CACNA1G, CALD1, NF1 and TNC (Figures 2B and 3A; see Additional file 8).