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.
Kris MG, Gralla RJ, Clark RA, Tyson LB.Kris MG, et al. Among authors: tyson lb.J Natl Cancer Inst. 1989 Jan 4;81(1):42-6. doi: 10.1093/jnci/81.1.42.J Natl Cancer Inst. 1989.PMID: 2521184Clinical Trial.