KMT6 / Enhancer of zeste homologue 2 (EZH2) is a histone lysine methyl transferase associated with transcriptional repression. It is a component of the polycomb repressive complexes PRC2 and PRC3. The PRC2 complex catalyses histone H3 K27 trimethylation. EZH2 is ubiquitously expressed during early embryo genesis, and becomes restricted to the central and peripheral nervous systems and sites of fetal hematopoiesis during later development. EZH2 is highly expressed in follicular T-cells and in a variety of tumors such as lymphoma, breast and prostate.