English: Host restriction factors involved in arenavirus infection. The IFITMs block entry at the sites of fusion within endosomal compartments or at the plasma membrane. Arenavirus particles, however, enter by trafficking through endosomal compartments that lack IFITM expression. Fusion in late endosomal compartments is inhibited by gamma-interferon-inducible lysosomal thiol reductase (GILT) expression. Viperin inhibits virion assembly by restricting the trafficking on arenavirus glycoproteins to the cell surface. Viperin also inhibits NP function by restricting recruitment of replication-transcription complexes orchestrated by NP, to lipid droplets. The membrane protein tetherin mediates retention of budding virions at the cell surface which are then proposed to be re-internalized and delivered to lysosomes for degradation.