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Schuster-Gossler K, Cordes R, Gossler A.Schuster-Gossler K, et al.Proc Natl Acad Sci U S A. 2007 Jan 9;104(2):537-42. doi: 10.1073/pnas.0608281104. Epub 2006 Dec 28.Proc Natl Acad Sci U S A. 2007.PMID: 17194759Free PMC article.