Disclosure forms provided by the authors are available with the full text of this article at NEJM.org.
No potential conflict of interest relevant to this article was reported.
This article was updated on April 26, 2018, at NEJM.org.
The opinions expressed in this article are those of the authors and do not necessarily reflect those of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the National Institutes of Health, the Department of Health and Human Services, or the U.S. Government.
We thank Dr. Avi Rosenberg of the NIDDK, Bethesda, MD, and Drs. Samih Nasr, Joseph Grande, Priya Alexander, and Mary Fidler of the Mayo Clinic, Rochester, MN, for the provision of clinical photomicrographs.