As sarcomere disruption and accumulation of desmin-positive protein aggregates are the major hallmarks of myofiber degeneration in plectin-related myofibrillar myopathies [3,13], we evaluated Z-disk appearance and the IF network distribution in teased extensor digitorum longus (EDL) fibers isolated from wild-type and P1d-KO mice using immunofluorescence microscopy for α-actinin or desmin, respectively (Figure 3A; see also [11]). This evidence concerns the gene DES and myopathy.