Among the most common, MLL-AF9 t(9;11) is mainly associated with AML in both paediatric and adult patients; MLL-AF4 t(4;11) is associated with a lymphoid/mixed-lineage phenotype (mainly ALL), and MLL-ENL t(11;19) drives paediatric ALL and adult AML (only a small fraction of adult patients develop MLL-ENL ALL) [70]. The gene discussed is AFF1; the disease is acute lymphoblastic leukemia.