Given that FSHD LCLs have expression of DUX4 and both early and late DUX4 target genes, and that FSHD muscle biopsies are often characterized by inflammation in a manner correlating with DUX4 target gene expression (33,49), we next investigated whether an FSHD LCL-derived gene expression signature can discriminate FSHD muscle biopsies from controls. The gene discussed is DUX4; the disease is facioscapulohumeral muscular dystrophy.