DES and myofibrillar myopathy: All these myofibrillar myopathy typical features were also present in homozygous R405W desmin knock‐in mice, however, at a much more pronounced level, including the myofibrillar (Figure 2e, f) and protein aggregation (Figure S2e, g) pathology, and abnormally shaped and enlarged mitochondria (Figure S2e–h, 3c,d ).