EZH2 and chronic myelogenous leukemia, BCR-ABL1 positive: However, contrary to this role, reports have also demonstrated that EZH2 is required for chronic myeloid leukemia stem cell function (Scott et al., 2016; Xie et al., 2016), and two separate studies have suggested that maintenance of MLL-AF9 AML is reliant on Ezh2 (Neff et al., 2012; Tanaka et al., 2012), suggesting EZH2 carries oncogenic function and is therefore a plausible therapeutic target in this context.