PTEN is a key tumor suppressor which inhibits cell proliferation and increases sensitivity to apoptosis.544,545 Alterations in PTEN function have been identified in a wide spectrum of tumors, indicating that it may control tumorigenesis.546 PTEN dysfunction leads to a prolonged PI3K/Akt signaling which induces abnormal cell growth and proliferation.547. The gene discussed is AKT1; the disease is neoplasm.