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Gibson MA, Gurmu E.Gibson MA, et al.Proc Natl Acad Sci U S A. 2011 Feb 8;108(6):2200-4. doi: 10.1073/pnas.1010241108. Epub 2011 Jan 24.Proc Natl Acad Sci U S A. 2011.PMID: 21262826Free PMC article.