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.
Swetloff A, Ferretti P.Swetloff A, et al. Among authors: ferretti p.Int J Dev Biol. 2005;49(7):859-65. doi: 10.1387/ijdb.051996as.Int J Dev Biol. 2005.PMID: 16172982Free article.
Ferretti P, Fekete DM, Patterson M, Lane EB.Ferretti P, et al.Dev Biol. 1989 Jun;133(2):415-24. doi: 10.1016/0012-1606(89)90045-6.Dev Biol. 1989.PMID: 2471654