USP7 and lung adenocarcinoma: Monoubiquitinated FoxO4 is deubiquitinated by HAUSP, and oxidative stress triggers the nuclear exclusion of FoxO4, negatively regulating its transcriptional activity.61 FoxO3a also interacts with HAUSP, suggesting that HAUSP may have a potential role in targeting the entire family of FoxO transcription factors and subsequent downstream functions.61 FoxO6 is downregulated in lung adenocarcinoma, and FoxO6 overexpression upregulates HAUSP and consequently facilitates p53 stabilization.100