EZH2 and osteosarcoma: It has been reported that EZH2 may be associated with distant metastasis and poor prognosis of human osteosarcoma16, 17; however, previous work has demonstrated that the knock-down of overexpressed EZH2 did not prevent osteosarcoma growth18, suggesting that EZH2 might not be a useful molecular target for osteosarcoma treatment.