Discovered in 1997 by two independent research groups,(55,56) the PTEN gene is a common deletion on chromosome 10.Monoallelic mutations are common in various types of cancer; however, homozygousPTEN mutations are frequently found in advanced cancers, such asendometrial cancer and glioblastoma.(57) Interestingly, PTEN is heavily regulated by variousgene regulation processes, such as RNA interference, methylation, acetylation,oxidation, and ubiquitination. Here, PTEN is linked to glioblastoma.