An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
LeBlanc DJ, Hawley RJ, Lee LN, St Martin EJ.LeBlanc DJ, et al.Proc Natl Acad Sci U S A. 1978 Jul;75(7):3484-7. doi: 10.1073/pnas.75.7.3484.Proc Natl Acad Sci U S A. 1978.PMID: 277950Free PMC article.