AFF1 and acute lymphoblastic leukemia: Based on the above distribution, about 94.3% of all ALL patients (n = 2182) were characterized by 6 fusion genes KMT2A::AFF1, KMT2A::MLLT1, KMT2A::MLLT3, KMT2A::MLLT10, KMT2A::AFDN and KMT2A::EPS15.