DUX4 and facioscapulohumeral muscular dystrophy: A previous study also suggests that LRIF1 may facilitate the interaction of SMCHD1 with HP1γ [41, 43] The activities of these molecules and perhaps others create structural chromatin changes that prevent the “leaky” sporadic DUX4 expression seen in FSHD due to incomplete repression by the PRC2 complex.