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Walker C, Selby M, Erickson A, Cataldo D, Valensi JP, Van Nest GV.Walker C, et al. Among authors: valensi jp.Proc Natl Acad Sci U S A. 1992 Sep 1;89(17):7915-8. doi: 10.1073/pnas.89.17.7915.Proc Natl Acad Sci U S A. 1992.PMID: 1518813Free PMC article.