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Braz JM, Rico B, Basbaum AI.Braz JM, et al.Proc Natl Acad Sci U S A. 2002 Nov 12;99(23):15148-53. doi: 10.1073/pnas.222546999. Epub 2002 Oct 21.Proc Natl Acad Sci U S A. 2002.PMID: 12391304Free PMC article.