Vol. 207, No. 2, February 8, 2010. Pages 417–427.
The authors regret that there was an error in the acknowledgements section of this article, and two National Institutes of Health grant numbers were listed incorrectly. The corrected acknowledgement is listed below, and the html and pdf versions of the article have been updated.
This work was supported by National Institutes of Health (NIH) grants AI077595 and CA092625 to F.W. Alt, AI037526 to M. Nussenzweig, and T32CA09382-26 to J.H. Wang. C. Boboila is supported by a Cancer Research Institute training grant. F.W. Alt and M. Nussenzweig are investigators of the Howard Hughes Medical Institute.