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Proc Natl Acad Sci USA 2009, 106(32):13410-13414. doi:10.1186/1471-2164-11-658 Cite this article as: Mannaert et al.: Comparative analyses of vertebrate posterior HoxD clusters reveal atypical cluster architecture in the caecilian Typhlonectes natans. BMC Genomics 2010 11:658.