When crossed with a skeletal muscle-specific, tamoxifen inducible cre-expressing mouse strain, skeletal muscles of the double transgenic offspring can be induced to produce mosaic expression patterns of DUX4-fl expression in a fraction of skeletal myonuclei, similar to the spontaneous mosaic bursting of DUX4-fl expression found in FSHD skeletal myocytes [14], ultimately resulting in an FSHD-like myopathy. This evidence concerns the gene DUX4 and facioscapulohumeral muscular dystrophy.