1. From the Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom (J.M.W.); Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, Stockholm, Sweden (V.M.); Department of Internal Medicine, Oslo University Hospital, Oslo, Norway (E.B.); and Division of Hematology, Departments of Medicine and Neurology, University of Washington, Seattle (G.J.d.Z.).