In summary, we detected two different patient myotube nuclei populations: (1) a set of 79 nuclei that express FSHD-induced genes (FSHD-Hi), 3 of which express endogenous DUX4 (DUX4+); (2) 60 nuclei that are clearly different from control nuclei but with no DUX4 detected and significantly lower FSHD-induced gene expression (FSHD-Lo). The gene discussed is DUX4; the disease is facioscapulohumeral muscular dystrophy.