KMT2A and acute lymphoblastic leukemia: We have confirmed that established primary aberrations allowed 30% of adult ALL to be assigned to well-defined risk subgroups, either to the bad prognosis subgroup (28%; KMT2A::AFF1 (MLL::AF4), BCR::ABL1-like phenotype, complex karyotype, and hyper-/hypodiploid karyotype); or the good prognosis subgroup with TCF3::PBX1; E2A::PBX1 (2%).