After challenge with ECTV, all Ifnar1-/-→ Rag1-/- mice quickly succumbed to infection whereas similar to Rag1-/- + B6 → Rag1-/-, most Rag1-/- + Ifnar1-/-→ Rag1-/- mice survived the infection (Fig 3G) with mild or no signs of disease. This evidence concerns the gene RAG1 and infection.