Nature Immunology 4, 907–912

In the September 2003 issue of Nature Immunology, the bars on the graph in Figure 3b were misidentified in the legend. The first sentence of the legend to Figure 3b should have read: “ROSA26 mice (five mice per group) were immunized by gene gun with DNA vaccines encoding Cre only (black bars), Cre and caspase 2 (open bars) or Cre and mutant caspase 2 (grey bars; apoptotic activity is 10% that of wild-type caspase 2).” This mistake does not affect the message of the paper.