IFNAR1 and infection: Much attention has been given to ZIKV infection in pregnant women and the corresponding fetal microcephaly and other associated diseases.720,721 IV or SC infection of ZIKV-infected pregnant IFNAR1−/− C57BL/6 mice caused placental infection, fetal brain injury, and fetal death.722 When IFNAR1 female mice were mated with WT sires, the resulting fetuses were considered IFNAR1 heterozygotes.