Likewise, it has been recently described for MLL-AF4+ infant B-ALL and TCF3-ZNF384+ B-ALL which both have a fetal liver hematopoietic stem cell as the cell-of-origin (Agraz-Doblas et al., 2019; Bueno et al., 2019). Here, KMT2A is linked to precursor B-cell acute lymphoblastic leukemia.