We thank Dr. Gilbert H. Daniels (Massachusetts General Hospital, Harvard Medical School, Boston, MA), Dr. Daniel S. Duick (Endocrinology Associates P.A., Scottsdale, AZ, and College of Medicine, University of Arizona, Phoenix and Tucson, AZ), and Dr. Sheldon S. Stoffer (Endocrine Consultant, William Beaumont Hospital, Oakland University William Beaumont School of Medicine, Oakland, CA) for their thoughtful suggestions. Dr. Daniels reports that he has received consultant fees from Genzyme Corporation. Dr. Duick reports that he has received speaker honoraria from Abbott Laboratories and consultant honoraria from Veracyte, Inc. and Asuragen, Inc. Dr. Stoffer reports that he does not have any relevant financial relationships with any commercial interests.