The CD8 lymphocyte infiltrates and diffuse increase in MHC class I labeling are more frequent in inflammatory myopathies, while in dystrophies, lymphocytic infiltrates are focal, and rarely have increased labeling for CD8 or MHC class I. Furthermore, in dystrophies, the finding of fibrosis between the fibers is more frequent and immunohistochemistry may be diagnostic by revealing the absence of muscle proteins (such as dysferlin, sarcoglycans, dystrophin). This evidence concerns the gene DMD and myopathy.