. 2012 Jun 25;9:142. doi: 10.1186/1742-2094-9-142
Copyright ©2012 Chen et al.; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.