Of further relevance, a significant subset of B-cell acute lymphoblastic leukaemia (B-ALL) cases present with a hybrid DUX4-IGH fusion gene in which the N-terminus-located homeodomains of DUX4 are fused to a clamp-like transactivation domain of IGH (43,44). Here, DUX4 is linked to precursor B-cell acute lymphoblastic leukemia.