PTEN and cancer: The tumour suppressor PTEN has been proved to be a target gene of EZH2, by which EZH2 could recruit H3K27me3 to the promoter of PTEN and inhibited the transcription of PTEN.47 PTEN is an inhibitor of PI3K/AKT pathway, which is frequently down-regulated or loss-of-functionally mutated in a variety of cancers.