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.
Varmus HE, Weiss RA, Friis RR, Levinson W, Bishop JM.Varmus HE, et al. Among authors: weiss ra.Proc Natl Acad Sci U S A. 1972 Jan;69(1):20-4. doi: 10.1073/pnas.69.1.20.Proc Natl Acad Sci U S A. 1972.PMID: 4333039Free PMC article.
Clapham P, Nagy K, Weiss RA.Clapham P, et al. Among authors: weiss ra.Proc Natl Acad Sci U S A. 1984 May;81(9):2886-9. doi: 10.1073/pnas.81.9.2886.Proc Natl Acad Sci U S A. 1984.PMID: 6326149Free PMC article.