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.
Zhang DE, Zhang P, Wang ND, Hetherington CJ, Darlington GJ, Tenen DG.Zhang DE, et al. Among authors: darlington gj.Proc Natl Acad Sci U S A. 1997 Jan 21;94(2):569-74. doi: 10.1073/pnas.94.2.569.Proc Natl Acad Sci U S A. 1997.PMID: 9012825Free PMC article.