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Khani SC, Zaphiropoulos PG, Fujita VS, Porter TD, Koop DR, Coon MJ.Khani SC, et al. Among authors: porter td.Proc Natl Acad Sci U S A. 1987 Feb;84(3):638-42. doi: 10.1073/pnas.84.3.638.Proc Natl Acad Sci U S A. 1987.PMID: 3027695Free PMC article.