EGFR and glioblastoma: To determine roles of histone modification in EGFR-driven gliomagenesis, we analyzed expression of histone H3 lysine 23 acetylation (H3K23ac), histone H3 lysine 27 trimethylation (H3K27me3), histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 acetylation (H3K27ac)-four histone modifications associated with transcriptional regulation8,19–23 using Western blotting in isogenic U87 and LN229 GBM cells with, or without, stable expression of the ligand-independent activated EGFR mutant, EGFRvIII.