While loss of JMJD1C was found to substantially decrease leukemic stem cell (LSC) frequency and induced differentiation of MLL-AF9-, HOXA9-, and AML1-ETO-driven leukemia (Chen et al., 2015; Sroczynska et al., 2014; Zhu et al., 2016), JMJD1C loss led to only minor defects in blood homeostasis and hematopoietic stem cell (HSC) self-renewal (Zhu et al., 2016). Here, MLLT3 is linked to leukemia.