MEF2A and facioscapulohumeral muscular dystrophy: MEF2A and E4BP4 DNA-binding motifs were enriched among FSHD-downregulated genes, which is consistent with the downregulation of MEF2A RNA in FSHD vs. control myotubes (Figure 7) and its role in myogenesis and the role of E4BP4/NFIL3 as a transcription repressor.