PRRs detect pathogen-associated molecular patterns (PAMPs) and signal the presence of infection to the host, activating host defense, including antiviral (IFN-α/β) and pro-inflammatory cytokine (interleukin-1β (IL-1β), IL-6, IL-18 and tumor necrosis factor α (TNF-α) production. Here, IFNA1 is linked to infection.