A closely related centronuclear myopathy similar to loss‐of‐function of MTM1 is due to dominant autosomal mutations in the endocytic IDP amphiphysin2/BIN1 (Lee et al, 2002; Nicot et al, 2007), possibly reflecting opposing roles of both proteins in the vesicular uptake and delivery of integrin molecules to the muscle surface. The gene discussed is MTM1; the disease is centronuclear myopathy.