AFF1 and acute lymphoblastic leukemia: Within the cohort of 117 consecutive patients with pediatric BCP-ALL, the following genetic markers relevant for inclusion/exclusion and risk stratification of patients were observed: BCR-ABL1 fusion (n = 1; exclusion criterion and referral to EsPhALL trial), ETV6-RUNX1 fusion (n = 26), AFF1-KMT2A fusion (n = 2), hypodiploidy (n = 1), and IKZF1plus (n = 12).