However, the number of proliferating T cells detected in the XCR1‐DTA mice was lower compared to the WT, suggesting that, as in the case of viral infections, despite the fact that type 2 DCs can prime CD8 T cells, type 1 DCs are still required for optimal T cell proliferation[29, 30] (Figure 1C). This evidence concerns the gene CD8A and viral infectious disease.