Barbara B Bendlin1, Henrik Zetterberg2. 1. From the Wisconsin Alzheimer's Disease Research Center (B.B.B.), University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison; Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry (H.Z.), Sahlgrenska Academy at University of Gothenburg; Clinical Neurochemistry Laboratory (H.Z.), Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease (H.Z.), University College London Institute of Neurology; and UK Dementia Research Institute at UCL (H.Z.), London, UK. bbb@medicine.wisc.edu. 2. From the Wisconsin Alzheimer's Disease Research Center (B.B.B.), University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison; Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry (H.Z.), Sahlgrenska Academy at University of Gothenburg; Clinical Neurochemistry Laboratory (H.Z.), Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease (H.Z.), University College London Institute of Neurology; and UK Dementia Research Institute at UCL (H.Z.), London, UK.