The recent discovery of several E3 ligases and deubiquitinases such as NEDD4-1, WWP2, XIAP, CHIP, SPOP, USP7 (HAUSP) and USP13 seems to imply that PTEN stability and subcellular localization are important in cancer development14, 16, 17, 18, 19, 20, 21. This evidence concerns the gene PTEN and cancer.