PTEN and cancer: In high grade serous ovarian cancer (HGSOC), the predominant type of ovarian cancer, it is estimated that the PI3K/AKT/mTOR pathway is activated in about half of cancers, with frequent amplifications in PIK3CA, AKT1, AKT2 and deletions in PTEN while mutations in the pathways components are relatively uncommon (<5% cancers)4–6,8.