EZH2 and acute lymphoblastic leukemia: Several genes encoding epigenetic regulators and chromatin modifiers are also recurrently mutated in T-ALL, including Enhancer of zeste homolog 2 (EZH2), suppressor of zeste 12 homolog (SUZ12) and embryonic ectoderm development (EED) [35], which are members of the polycomb repressor complex 2 (PRC2); the plant homeodomain factor gene PHF6 [36]; the histone demethylase lysine demethylase 6A (KDM6A) [37]; and the deubiquitinating enzyme ubiquitin specific peptidase 7 (USP7) [38].