Translocations t(9;22)(q34;q11) [BCR-ABL1], t(12;21)(p13;q22) [ETV6-RUNX1 (TEL-AML1)], hyperdiploidy, and translocation t(4;11)(q21;q23) [MLL-AFF1(AF4)] in infants, are found at the highest frequency in childhood B-ALL [11]. The gene discussed is KMT2A; the disease is precursor B-cell acute lymphoblastic leukemia.