In a retrospective analysis of 939 patients with ETV6::RUNX1 and 968 patients with HeH B-ALL across 16 clinical trials between 1991–2016, IKZF1 deletions were detected in 3% of ETV6::RUNX1 and 9% of HeH patients [66]. Here, IKZF1 is linked to acute lymphoblastic leukemia.