STAT1 and infection: STAT1(-/-) miceare highly sensitive to MPXV and the disease course in MPXV infected STAT1(-/-) mice, characterized by weight loss and death by day 10 post infection—is similar to that observed in wild-type mice infected with mousepox/ectromelia virus (ECTV), the etiology agent of mousepox—and probably the best small animal model of smallpox [35,57].