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.
Morris CM, Honeybone LM, Hollings PE, Fitzgerald PH.Morris CM, et al. Among authors: hollings pe.Blood. 1989 Oct;74(5):1768-73.Blood. 1989.PMID: 2506951Free article.