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Danforth BN.Danforth BN.Proc Natl Acad Sci U S A. 2002 Jan 8;99(1):286-90. doi: 10.1073/pnas.012387999. Epub 2001 Dec 26.Proc Natl Acad Sci U S A. 2002.PMID: 11782550Free PMC article.