In the absence of TMX, TIC-DUX4 mice showed a low level of DUX4 expression only when old (>1.5 years), while TMX-treated TIC-DUX4 mice developed the typical histological and functional phenotype of an FSHD-like muscular disorder [136]. The gene discussed is TMX1; the disease is facioscapulohumeral muscular dystrophy.