In acute lymphoblastic leukemia (ALL) patients, the human mixed lineage leukemia gene (MLL) often undergoes chromosomal rearrangements at the chromosome band 11q23, which leads to unique clinical and biological features and unfavorable prognosis.[1,2] Overall, MLL rearrangements are found in ∼10% of human leukemia cases. This evidence concerns the gene KMT2A and acute lymphoblastic leukemia.