DUX4 and facioscapulohumeral muscular dystrophy: Accomplishing this required two new sets of reagents: (i) antagomirs, which are small oligonucleotides used to silence endogenous miRNAs; and (ii) three human myoblast cell lines, including two from FSHD-affected patients (15A and 17A) that express sporadic and low levels of endogenous DUX4; and an unaffected, DUX4-negative control myoblast line (15V)39,40.