KMT2A and leukemia: These results demonstrate that using CRISPR/Cas9 to induce MLL translocations in HSPCs derived from huBM leads to expression of the fusion transcript, upregulation of KMT2Ar-specific target genes, a myelomonocytic phenotype and immature morphology hereby authentically mimicking KMT2Ar leukemia; therefore, this model can be used as a reliable patient-derived in vitro model.