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.
Trotter EW, Berenfeld L, Krause SA, Petsko GA, Gray JV.Trotter EW, et al. Among authors: gray jv.Proc Natl Acad Sci U S A. 2001 Jun 19;98(13):7313-8. doi: 10.1073/pnas.121172998.Proc Natl Acad Sci U S A. 2001.PMID: 11416208Free PMC article.