It has long been known that defective variants at 13 genetic loci contribute to the development of influenza virus-induced severe pneumonia (IRF7, IRF9 and TLR3 genes), adverse events to live attenuated virus vaccines (IFNAR1, IFNAR2, STAT2 genes) or herpes simplex encephalitis (TLR3, UNC93B1, TICAM1, TRAF3, TBK1, IKBKG, IRF3, IFNAR1, STAT1 genes). The gene discussed is IFNAR1; the disease is herpes simplex encephalitis.