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Hellmich RL, Siegfried BD, Sears MK, Stanley-Horn DE, Daniels MJ, Mattila HR, Spencer T, Bidne KG, Lewis LC.Hellmich RL, et al.Proc Natl Acad Sci U S A. 2001 Oct 9;98(21):11925-30. doi: 10.1073/pnas.211297698. Epub 2001 Sep 14.Proc Natl Acad Sci U S A. 2001.PMID: 11559841Free PMC article.