PTEN and glioma: Intensive research over the last three decades, especially recent research by TCGA, has revealed a large number of putative oncogenes and tumor suppressor genes that are altered in glioma, such as EGFR, PDGFRα, IGFBP2, c-Myc, Cdc20, and Akt3 oncogenes and CDKN2A, PTEN, and NF1 tumor suppressor genes.