The enzyme phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase (EC 3.1.3.67) catalyzes the chemical reaction This enzyme class belongs to the family of hydrolases, specifically those acting on phosphoric monoester bonds. The systematic name is 1-phosphatidyl- D -myoinositol-3,4,5-trisphosphate 3-phosphohydrolase. Other names in common use include PTEN, MMAC1, and phosphatidylinositol-3,4,5-trisphosphate 3-phosphohydrolase. PTEN also refers to a member of the class, phosphatase and tensin homolog. This enzyme participates in 10 metabolic pathways: inositol phosphate metabolism, phosphatidylinositol signaling system, p53 signaling pathway, focal adhesion, tight junction, endometrial cancer, glioma, prostate cancer, melanoma, and small cell lung cancer. It employs one cofactor, magnesium.