Addendum to: Nature Immunology https://doi.org/10.1038/ni1478. Published 10 June 2007.

The Editor would like to alert the readers that concerns have been raised regarding high similarity between the ATM blots in Figs. 2b and 3b Ly7, which represent similar levels of ATM across all groups. Although this does not affect the conclusions of the article, readers are advised to interpret this result with caution.

Stella Maris Ranuncolo, Jose M. Polo, Martin Carroll and Ari Melnick agree to this Editorial Expression of Concern. Tracy Kuo, John Greally and Roland Green have not responded to any correspondence from the editor or publisher about this Editorial Expression of Concern. The publisher has been unable to obtain current email addresses for Jamil Dierov and Michael Singer.