PTEN and neoplasm: In particular, the post-translational modifications of wild-type PTEN (e.g., phosphorylation, mono- or poly-ubiquitination, sumoylation, oxidation and acetylation) are known to tightly regulate the function of the tumor suppressor as the result of altered subcellular localization, protein/protein interaction and/or phosphatase activity, independently of PTEN accumulation [10].