Since most LACV infections in humans are subclinical with only a small proportion of infected children developing encephalitis, the clinical outcome of LACV infection could be dependent on the degree of IFN production and the magnitude of IFN-induced antiviral effector proteins, including but not limited to MxA or PKR, in limiting peripheral LACV replication and virus spread to the CNS. The gene discussed is IFNA1; the disease is encephalitis.