Although two wild type RNA viruse induce production of abundant vsiRNAs in undifferentiated cells [24,26], production of vsiRNAs in the IFN-defective mouse ESCs induced by NoV infection is potently suppressed by the cognate VSR protein B2 [24], suggesting widespread suppression of vsiRNA biogenesis during mammalian virus infection [6,20]. Here, IFNA1 is linked to viral infectious disease.