Infection of the progeny mice born to naïve KitW-sh/W-sh Ifnar1−/− Ifngr1+/+ mothers, with DENV2(D2Y98P) s.c., resulted in 30% mortality, compared to 90% mortality in KitW-sh/W-sh Ifnar1−/− Ifngr1−/− mice (Figure 4B) and lower clinical score (Figure 4C), indicating the protective property of IFN-γ signaling. This evidence concerns the gene IFNAR1 and infection.