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Reeve HK, Pfennig DW.Reeve HK, et al.Proc Natl Acad Sci U S A. 2003 Feb 4;100(3):1089-94. doi: 10.1073/pnas.0337427100. Epub 2003 Jan 22.Proc Natl Acad Sci U S A. 2003.PMID: 12540829Free PMC article.