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Carroll J, Fearnley IM, Walker JE.Carroll J, et al.Proc Natl Acad Sci U S A. 2006 Oct 31;103(44):16170-5. doi: 10.1073/pnas.0607719103. Epub 2006 Oct 23.Proc Natl Acad Sci U S A. 2006.PMID: 17060615Free PMC article.