EZH2 and cancer: Polycomb repressor complex 2 (PRC2) includes three core components: enhancer of zeste homolog 2 (EZH2), SUZ12 and EED, and functions as a pivotal regulator of cell growth, survival and differentiation.1 As a histone lysine methyltransferase, EZH2 is a major catalytic component of PRC2 and mediates trimethylation on histone 3 lysine 27 (H3K27me3), resulting in the silencing of mostly tumor-suppressing genes.2 High EZH2 levels are found in many human malignant solid tumors and positively correlate with the initiation, as well as drug resistance of cancer, indicating poor prognosis.