Transgenic animals, but not their control littermates, exhibited a strong increase in RNF5 expression in muscle fibers within areas of regeneration including rimmed vacuoles and centrally located nuclei (Fig. 1F), characteristic of this model [24].These findings reveal altered RNF5 expression in specific degenerative myopathies associated with dysfunction of the ER or the ERAD machinery such as sporadic and hereditary IBM. Here, RNF5 is linked to inclusion body myositis.