2° Att LM infection resulted in a 2° CD8 T cell response as percentages of CD8lo/CD11ahi cells were increased 7 days following 2° Att LM infection in both inbred and outbred mice (Figure 10B), and while size of the memory CD8 T cell pool was still variable in individual Swiss mice, resulted in a larger memory CD8 T cell pool that was significantly different between naïve Swiss mice and Swiss mice that received 2° Att LM infection (Figure 10C). This evidence concerns the gene CD8A and infection.