Tumorigenesis is the result of abnormal activation of growth programs in the cells. Cancer cells escape normal growth control mechanisms as a consequence of activating mutations, or increased expression of one or more cellular protooncogenes, and/or inactivating mutations, or decreased expression of one or more tumor suppressor genes. Most oncogene and tumor suppressor gene products are components of signal transduction pathways that control cell cycle entry or exit, promote differentiation, sense DNA damage and initiate repair mechanisms, or regulate cell death programs. PTEN (Phosphatase and Tensin Homologue Deleted from Chromosome-10)/MMAC1 (Mutated in Multiple Advanced Cancers-1)/TEP1 (TGF-Beta Regulated and Epithelial Cell Enriched Phosphatase-1) has recently been identified as one of the most frequently mutated tumor suppressors in human cancer that functions primarily as [...]