The polycomb repressive complex 2 (PRC2) binds chromatin and represses PTEN transcription in nasopharyngeal epithelial cells and leukemia through enhancer of zeste homolog 2 (EZH2)-mediated trimethylation of histone 3 lysine 27 (H3K27Me3) at the PTEN promoter24,25, and is reported to be guided to the site of action at the PTEN locus by long noncoding RNA (lncRNA) originating from the PTENP1 pseudogene locus in certain contexts26. This evidence concerns the gene PTEN and leukemia.