DUX4 aberrant reactivation or gene rearrangements are associated with several diseases, including infection by viruses of the Herpesviridae family [6,7], acute lymphoblastic leukemia [8,9,10], undifferentiated round cell sarcoma [11], several neoplasms [12,13,14] and facioscapulohumeral muscular dystrophy (FSHD) (Figure 1) [15]. Here, DUX4 is linked to acute lymphoblastic leukemia.