TFRC and hemorrhagic fever: The clade B New World arenaviruses (NWAs), including Junín and Machupo viruses—the causative agents of Argentine and Bolivian hemorrhagic fever, respectively—use human but not mouse (Mus) transferrin receptor 1 (TfR1) for cell entry [2], whereas the Old World arenaviruses (OWAs) Lassa virus and lymphocytic choriomeningitis virus (LCMV) use alpha-dystroglycan [3].