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.
Chu ZL, McKinsey TA, Liu L, Gentry JJ, Malim MH, Ballard DW.Chu ZL, et al. Among authors: ballard dw.Proc Natl Acad Sci U S A. 1997 Sep 16;94(19):10057-62. doi: 10.1073/pnas.94.19.10057.Proc Natl Acad Sci U S A. 1997.PMID: 9294162Free PMC article.