We unexpectedly found that like the WT mice, the Mda5–/– and Mavs–/– mice were sensitive to lethal N67C infections (Figure 1A,B) and died within 10 days p.i. Similarly, the Tlr7–/– and Tlr9–/– mice were sensitive to N67C infections and died within 10 days p.i. (Figure S1A,B, Supporting Information). This evidence concerns the gene TLR9 and infection.