ETV6::RUNX1 B-ALL with co-occurring IKZF1 deletion was associated with a 5-year EFS of 79% (versus 92% in those without an IKZF1 deletion), though measurable residual disease (MRD) stratification negated this adverse outcome for patients treated using MRD-guided protocols [66]. The gene discussed is IKZF1; the disease is acute lymphoblastic leukemia.