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Higgins GA, Oyler GA, Neve RL, Chen KS, Gage FH.Higgins GA, et al. Among authors: chen ks.Proc Natl Acad Sci U S A. 1990 Apr;87(8):3032-6. doi: 10.1073/pnas.87.8.3032.Proc Natl Acad Sci U S A. 1990.PMID: 1970179Free PMC article.