. Author manuscript; available in PMC: 2014 Mar 1.
Published in final edited form as: Genes Immun. 2013 May 9;14(6):347–355. doi: 10.1038/gene.2013.22
Users may view, print, copy, download and text and data- mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use: http://www.nature.com/authors/editorial_policies/license.html#terms