On page2936 of the November 1, 2005, issue, in the first sentence of the first paragraph of “Materials and methods,” the primer sequence described for cloning the CTLA4 KDEL construct is incorrect. In the paper, the second sequence given was 5′-TTTTTGTTCTGCGGCCGCCAATTACATAAATCTG-GGTTCCGT-3′. The actual primer sequence used was 5′-TTTTTGTTCTGCGGCCGCAATTACATAAATCTGGGTTCCGT-3′.