IFNGR1 and dengue disease: To investigate how MCs influence maternal antibody-mediated dengue disease, we first generated mice that lacked both MCs and IFN receptors by crossing AG129 (Ifnar1−/− Ifngr1−/−) mice with MC-deficient Sash (KitW-sh/W-sh), and the F1 progeny were then crossed with each other.