DUX4 and facioscapulohumeral muscular dystrophy: Himeda et al. used lentiviral delivery of dCas9-KRAB to the DUX4 promoter or exon 1 in FSHD myocytes derived from patient bicep muscle and demonstrated reduced expression of DUX4-fl to ~45% of endogenous levels in FSHD myocytes [182].