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Siebold C, García-Alles LF, Erni B, Baumann U.Siebold C, et al.Proc Natl Acad Sci U S A. 2003 Jul 8;100(14):8188-92. doi: 10.1073/pnas.0932787100. Epub 2003 Jun 17.Proc Natl Acad Sci U S A. 2003.PMID: 12813127Free PMC article.