Transferrin receptor 1 in the zoonosis and pathogenesis of New World hemorrhagic fever arenaviruses

► Transferrin receptor 1 (TfR1) is the cellular receptor for New World hemorrhagic fever arenaviruses. ► Commonalities between human TfR1 and TfR1 of arenaviral host species make zoonoses possible. ► TfR1 upregulation during the acute-phase response may amplify arenaviral replication. ► TfR1 may make a useful target for much needed therapies for arenaviral hemorrhagic fevers.