EZH2 and acute lymphoblastic leukemia: Although EZH2 is overexpressed in many solid cancers, including breast, lung, and liver cancer (Eich et al., 2020), loss-of-function mutations of EZH2, inactivating mutations, or deletion of this epigenetic modifier is commonly present in human T-ALL cells (Ntziachristos et al., 2012; Girardi et al., 2017).