Genomic DNA aberrations are key genetic events in gliomagenesis. Recurrent genomic regions of alteration, including net gains and losses, have been found in gliomas. Whereas some of these regions contain known oncogenes and tumor suppressor genes, the biologically relevant genes within other regions remain to be identified. The phenotypic and genotypic heterogeneity indicate that no isolated genetic event accounts for gliomagenesis, but rather the cumulative effects of a number of alterations that operate in a concerted manner. In this pathological process are included various biological events, such as activation of growth factor receptor signaling pathways, down-regulation of many apoptotic mechanisms,...