54-6 control (non-FSHD) myoblasts that lack DUX4 were transfected with a DUX4 expression vector and DUX4 activity monitored by measuring mRNA levels of the endogenous DUX4 target gene MBD3L2. Compounds were added 5 h after transfection, a time at which there is little detectable MBD3L2 expression, and mRNA levels assessed at 24 h after transfection. The gene discussed is MBD3L2; the disease is Facioscapulohumeral dystrophy.