IDH1 and glioblastoma: The observed patterns of DNA changes, DNA methylation, and copy number alterations suggest an ordered molecular evolution of IDH1(R132MUT) GBM in which the appearance of mutant IDH1 protein in spatially and temporally restricted neural precursors is an initial event, followed by production of TP53 mutant protein, and finally by copy number alterations of PTEN and EGFR [80].