MLLT3 and leukemia: The leukemia was characterized by the most immature B-lineage immunophenotype [pro-B ALL/B-I, according to the European Group for the Immunological Characterization of Leukaemias (EGIL) classification] and chromosomal translocation t(9;11)(p22;q23), resulting in fusion gene <i>KMTLA2::MLLT3</i>, which is considered a negative prognostic factor.