Acknowledgments
This article is not subject to US copyright law.
This project has been funded in part with federal funds from the National Cancer Institute, National Institutes of Health, under contract No. HHSN261200800001E. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services or the Food and Drug Administration, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.