To address this need, we used our recently developed tamoxifen (TMX)-inducible DUX4 bi-transgenic mouse line, ACTA1-MCM;FLExD, that recapitulates many aspects of FSHD pathophysiology of varying severity in skeletal muscles (Jones et al., 2020). The gene discussed is ACTA1; the disease is facioscapulohumeral muscular dystrophy.