However, FSHD iMyoblasts and bMyoblasts were responsive to inhibition of DUX4 target gene expression by the p38 inhibitor, Losmapimod, currently in FSHD clinical trials (Rojas, 2019; Figure 5—figure supplement 1), showing that FSHD1 iMyotubes and bMyotubes share multiple pathways for DUX4 regulation that are suitable for drug development targeting DUX4 expression. Here, DUX4 is linked to facioscapulohumeral muscular dystrophy.