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.
Friedman RM, Chen LM, Roe AW.Friedman RM, et al. Among authors: chen lm.Proc Natl Acad Sci U S A. 2004 Aug 24;101(34):12724-9. doi: 10.1073/pnas.0404884101. Epub 2004 Aug 12.Proc Natl Acad Sci U S A. 2004.PMID: 15308779Free PMC article.