The most common genetic alterations in gliomas are EGFR (epidermal growth factor receptor) and MDM2 (murine double minute 2) amplifications, TP53, PTEN (phosphatase and tensin homolog) and IDH 1/2 mutations, loss of heterozygosity (LOH) of chromosome 10q, 1p/19q codeletion and MGMT (O6-methylguanine-DNA methyltransferase) promoter methylation [33]. The gene discussed is PTEN; the disease is glioma.