PTEN and neoplasm: Ubiquitin-Specific Protease 7 (USP7, also known as HAUSP, the herpes virus-associated USP) has been implicated in deubiquitylation of PTEN as well as other tumor suppressors such as p53 and FOXO by reversing mono-ubiquitylation and thus regulates several crucial cancer-related signaling pathways [20].