Through its IRF-8 association domain (IAD), IRF-8 interacts with other transcription factors, such as PU-1, IRF-1, IRF-4, and IRF-2, and plays an important role in immunity against tumors and infections with intracellular pathogens, including bacteria, viruses, and protozoan parasites [4–6]. The gene discussed is IRF8; the disease is infection.