DUX4 and facioscapulohumeral muscular dystrophy: Various groups have since capitalized on using conditional methods to overexpress DUX4 in mice, allowing for more refined control of DUX4 toxicity and ushering in the production of FSHD animal models amenable to pre-clinical study (Bosnakovski et al., 2017a; Bosnakovski et al., 2020; Giesige et al., 2018; Jones and Jones, 2018).