AFF1 and acute lymphoblastic leukemia: Of note, the 2010–2020 guidelines for childhood ALL subtyping required testing for only the five most frequent and validated prognostic subgroups (ETV6::RUNX1, BCR::ABL1 (p190 and p210), KMT2A::AFF1, hyperdiploid and hypodiploid), limiting the confirmation of the 13 additional subtypes assigned by ALLSorts.