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.
Heck DH, Thach WT, Keating JG.Heck DH, et al. Among authors: thach wt.Proc Natl Acad Sci U S A. 2007 May 1;104(18):7658-63. doi: 10.1073/pnas.0609966104. Epub 2007 Apr 23.Proc Natl Acad Sci U S A. 2007.PMID: 17452649Free PMC article.