Nature Reviews Immunology 2, 909–919 (2002)

Three figures in this article are labelled incorrectly: •In Figure 3b, page 913, the second and third transgenic constructs should have the following activity patterns in the thymus: for the second construct, DN + DP + CD4 + CD8 +; and for the third construct, DN − DP − CD4 + CD8 +. •In Figure 4a, page 915, the labels for Cd8a and Cd8b should be reversed, such that Cd8b lies upstream of Cd8a. •In Figure 5, page 917, the second chromatin structure should be labelled as CD4CD8+ ISP, not as CD4CD8 ISP.

The online versions of these figures have been corrected.