Enhancer of zeste homolog 2 (EZH2), as one of the most well-characterized epigenetic regulators, is the catalytic subunit of the Polycomb Repressive Complex 2 (PRC2) which functions to silence target genes by tri-methylating lysine 27 of histone H3 (H3K27me3). EZH2 plays a critical function in development and adult tissue homeostasis, and is closely associated with many diseases. Studies have found that EZH2 is highly expressed in a variety of solid tumors and hematological malignancies and is closely related to tumor proliferation, invasion, metastasis and poor prognosis. Therefore, EZH2 provides a pharmacological target for cancers.