Studies that have compared benign astrocytoma, low-grade glioma and high-grade glioma (glioblastoma multiforme) have highlighted potentially important genetic events associated with glioma progression, such as methylation of DNA methylase 1 (DNAMT1), methyl guanine methyl transferase (MGMT) and EGFR promoters, chromosomal losses and gains, IDH1 mutations in low-grade astrocytoma [32, 60–62]. Here, IDH1 is linked to glioma.