PTEN and glioblastoma: PTEN (phosphatase and tensin homolog deleted on chromosome 10, also called MMAC1 or TEP1) is a tumor suppressor gene [28-30], which is frequently deleted or mutated in a wide range of human cancers, including glioblastoma [31], melanoma [32], and prostate [33], breast [34], and endometrial cancers [35].