PTEN and neoplasm: PTEN encodes the phosphatidylinositol 3,4,5-trisphosphate 3-phosphatase and dual-specificity protein phosphatase PTEN (PTEN), which functions as a tumor suppressor by negatively regulating PI3K-AKT signaling (Maehama and Dixon, 1998; Stambolic et al., 1998).