None of these models mimics the typical situation in FSHD in which pathology is caused by sporadic, but chronic, expression of DUX4 in skeletal muscles throughout one's lifetime (Haynes et al., 2018; Jones et al., 2012; Rickard et al., 2015; Snider et al., 2010; Tassin et al., 2013). This evidence concerns the gene DUX4 and facioscapulohumeral muscular dystrophy.