DUX4 and facioscapulohumeral muscular dystrophy: While no transgenic mouse model expressing DUX4 and showing signs of a myopathy were available in 2016, several research groups are developing new transgenic mouse models that appear much closer to the pathological presentation of FSHD and could potentially be used to evaluate AOs of different chemistries in vivo for efficacy, specificity and lack of toxicity.