Because of its pathophysiological similarities to DUX4-induced FSHD, ACTA1-MCM/FLExDUX4 mouse (hereafter referred to as DUX4-TG mouse) was recently established as an FSHD model, and is of increasing preclinical interest [9,10]. The gene discussed is ACTA1; the disease is facioscapulohumeral muscular dystrophy.