In recent weeks, studies showed that young or adult immunocompetent mice are not susceptible to infection, but prepubescent mice lacking the capacity to produce or respond to interferons (IFNs), including A129 (type I IFNAR KO), Interferon Regulatory Factor (IRF)3/5/7 triple KO, and AG129 (type 1 and type 2 IFN KO), develop neurological disease and succumb to infection with high viral loads in the brain, spinal cord, and testes [14,15]. The gene discussed is IRF3; the disease is infection.