In the version of this Article originally published, the affiliations for Roland A. Fleck and Jos Antonio Del Ro were incorrect due to a technical error that resulted in affiliations 8 and 9 being switched. The correct affiliations are: Roland A. Fleck: 8Centre for Ultrastructural Imaging, Kings College London, London, UK. Jos Antonio Del Ro: 2Cellular and Molecular Neurobiotechnology, Institute for Bioengineering of Catalonia, Barcelona, Spain; 9Department of Cell Biology, Physiology and Immunology, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; 10Centro de Investigacin Biomdica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain. This has now been amended in all online versions of the Article.