PTEN and glioblastoma: Moreover, PTEN mutations are frequently observed in a wide variety of sporadic cancers, such as glioblastoma (GBM) (20%), malignant melanoma (15%), endometrial (20%), prostate (20%), breast (7%), colorectal (6%) and pancreatic (1.4%) (data obtained from genomic datasets in the cBioPortal for Cancer Genomics are reported in Table 1) [9,10].