DUX4 and facioscapulohumeral muscular dystrophy: We then tested the effect of the three molecules on the expression of endogenous miR-675-5p, DUX4 and DUX4-responsive biomarker, TRIM43 in 15A, 18A, and 17A FSHD differentiated muscle cell lines (myotubes), which express different levels of DUX4 (15A < 18A < 17A) (Fig. 9)39.