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.
Li GC, Li LG, Liu YK, Mak JY, Chen LL, Lee WM.Li GC, et al. Among authors: mak jy.Proc Natl Acad Sci U S A. 1991 Mar 1;88(5):1681-5. doi: 10.1073/pnas.88.5.1681.Proc Natl Acad Sci U S A. 1991.PMID: 1705702Free PMC article.