Although in one experiment, there was no difference in the ability of the WT and IL-21R−/− CD8+ T cells to transfer protection (Fig. 6h, i), this experimental approach was limited by the development of a wasting syndrome in the TCRα−/− mice infused with IL-21R−/− CD8+ T cells, which was independent of infection (Fig. 6j). Here, CD8A is linked to infection.