NEDD4 and urinary bladder neoplasm: Increasing levels of NEDD4‐1 significantly reduced PTEN expression and potentiated cell proliferation and prostate/bladder tumor formation, suggesting an oncogenic role of NEDD4‐1 in regulating PTEN functions.49, 50 Besides degradation, NEDD4‐1 can also monoubiquitinate PTEN to regulate it into the nucleus.35However, subsequent studies have shown no difference in the stability and localization of PTEN in two different strains of NEDD4‐1‐deficient mice.51 In our study, we found that Bor increased the expression of PTEN in the shRNA group but to a lesser extent than in the controls.