DUX4 and facioscapulohumeral muscular dystrophy: Examining mRNA levels of these eight DUX4 target genes in scRNAseq (van den Heuvel et al., 2019) and snRNAseq (Jiang et al., 2020) studies of FSHD and control differentiated myoblasts, expression was restricted to FSHD cells/nuclei and never observed in controls.