1. Kidney Research Institute and Division of Nephrology (I.H.d.B., M.C.S.), Department of Medicine, University of Washington, Seattle, Washington 98104
2. The George Washington University (P.A.C., J.M.L., W.S.), Rockville, Maryland 20852
3. Departments of Laboratory Medicine and Medicine (A.N.H.), University of Washington, Seattle, Washington 98104
4. Northwestern University (M.E.M.), Chicago, Illinois 60611
5. Department of Laboratory Medicine (M.W.S.), University of Minnesota, Minneapolis, Minnesota 55455
6. Samuel Lunenfeld Research Institute (B.Z.), Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada M5G 1X5
7. Division of Metabolism, Endocrinology, and Nutrition (J.D.B.), Department of Medicine, University of Washington, Seattle, Washington 98104