Comparing B-ALL with iAMP21 versus B-ALL patients with coexistent iAMP21 and ETV6-RUNX1, the iAMP21 only patients had a younger age at disease onset; 9 years old for iAMP21 versus 15 years old for coexistent iAMP21 and ETV6-RUNX1, p = 0.00. Here, RUNX1 is linked to acute lymphoblastic leukemia.