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Popkin DL, Watson MA, Karaskov E, Dunn GP, Bremner R, Virgin HW 4th.Popkin DL, et al.Proc Natl Acad Sci U S A. 2003 Nov 25;100(24):14309-14. doi: 10.1073/pnas.1835673100. Epub 2003 Nov 12.Proc Natl Acad Sci U S A. 2003.PMID: 14614150Free PMC article.