The outcomes of BCP-ALL patients differ by genetic subtype, i.e., ETV6::RUNX1(E/R), high hyperdiploidy, and TCF3::PBX1 patients have favorable prognoses, while BCR::ABL1- and KMT2A-rearranged BCP-ALL patients are associated with unfavorable treatment outcomes. The gene discussed is KMT2A; the disease is acute lymphoblastic leukemia.