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.
Thorens B.Thorens B.Proc Natl Acad Sci U S A. 1992 Sep 15;89(18):8641-5. doi: 10.1073/pnas.89.18.8641.Proc Natl Acad Sci U S A. 1992.PMID: 1326760Free PMC article.