DUX4 and facioscapulohumeral muscular dystrophy: Since 2011, several studies have shown that these RNAi-based oligos can knockdown DUX4 mRNA and reduce DUX4 transactivation, in addition to improving other markers of FSHD symptom reversal (e.g., DUX4 protein levels, muscle fiber health, murine functional performance, etc.)(Table 2) [25,26,39,40,41,42,43,44,45,46,47,48].