EZH2 is the catalytic core protein in the Polycomb Repressor Complex 2 (PRC2), which catalyses the trimethylation of histone3 lysine27 (H3K27) and mediates gene silencing of the target genes that are involved in fundamental cellular processes, such as cell fate decision, cell cycle regulation, senescence, cell differentiation and cancer (Sauvageau and Sauvageau, 2010). The gene discussed is EZH2; the disease is cancer.