DUX4 and facioscapulohumeral muscular dystrophy: Ectopic expression of DUX4 in human myocytes drives activation of immune‐related genes (Geng et al, 2012), and DUX4 target genes are upregulated in actively inflamed STIR‐positive FSHD muscle biopsies (Banerji & Zammit, 2019).