Additionally, Ret, GFRα1 and GFRα2 are expressed in the retina and the sensory epithelium of the cochlea, both of which can be affected in FSHD (Golden et al., 1999; Zordan et al., 2006; Yu et al., 1998). This evidence concerns the gene GFRA1 and facioscapulohumeral muscular dystrophy.