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Metzger DE, Stahlman MT, Shannon JM.Metzger DE, et al. Among authors: shannon jm.Dev Biol. 2008 Aug 1;320(1):149-60. doi: 10.1016/j.ydbio.2008.04.038. Epub 2008 May 10.Dev Biol. 2008.PMID: 18544451Free PMC article.