RAG1 and infection: YAC-CD46 mice were crossed into different immunodeficient backgrounds (recombination activating gene 1 (RAG-1) knockout (KO), CD4-KO, CD8-KO, breakpoint cluster region protein (BCR)-KO, Perforin-KO, tumor necrosis factor (TNF)-α KO, interferon (IFN)-γ KO) [81] and it was found that the interferon response and downstream adaptive immunity were critical in controlling infections.