DUX4 and facioscapulohumeral muscular dystrophy: It was critically important that we found these BSS assays to be specific to 4q (4qA and 4qA-L BSS assays) or 4q/10q D4Z4s (DUX4 5′ BSS assay), as indicated by the >99.8% coverage of expected CpGs when compared to the reference sequences (Figures 3, 4, 5, and 6; Additional file 1: Figures S1 and S2), because there are D4Z4 homologs on chromosomes 3, 13, 14, 15, 21, 22, and Y which do not show epigenetic changes in FSHD [49].