PTEN and cancer: Activation of PI3K/Akt signaling, which promotes cancer formation and growth, is achieved through a variety of mechanisms that includes inactivation of Phosphatase and Tensin homolog deleted on chromosome 10 (PTEN), a lipid phosphatase that converts phosphatidylinositol-3,4,5-trisphosphate to phosphatidylinositol-4,5-bisphosphate that antagonizes PI3K/Akt signaling.