In contrast to other myosin isoforms, the so-called “non-muscle myosin” MYH9 (NMHC-A) showed increased relative abundance in atrophic FSHD myotubes, as were the MYL6, MYL9 and MYL12B light chains. This evidence concerns the gene MYL12B and facioscapulohumeral muscular dystrophy.