DNM2 and inclusion body myositis: However, the biological significance of so few affected fibres in a standard biopsy section is questionable: more than 75% of fibres are affected in many humans with MFM,38, 39 and low levels of desmin and other cytoskeletal protein aggregation are often seen as non‐specific features of non‐desmin‐related myopathies such as inclusion body myositis,71 central core72 and minicore myopathies.73