. 2010 Sep 17;17(1):75. doi: 10.1186/1423-0127-17-75
Copyright ©2010 Li 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.