Line #7, which displayed consistent X-gal staining in the embryonic limbs and face, showed weak X-gal staining in adult muscles and strong X-gal staining in testis, without apparent staining in other non-muscle tissues, recapitulating what is known about DUX4 expression in FSHD patients. The gene discussed is DUX4; the disease is facioscapulohumeral muscular dystrophy.