Antiretroviral restriction factors in mice

•We briefly discuss “restriction factors” that block retrovirus replication in mice.•The restriction factors reviewed are Fv1, APOBEC3, and Tetherin.•We review their modes of action and evolutionary origins.

One of the most exciting areas in contemporary retrovirus research is the discovery of “restriction factors”. These are cellular proteins that act after virus entry to inhibit infection by or replication of retroviruses (and other viruses and intracellular pathogens). We briefly discuss here three antiretroviral restriction factors in mice: Fv1, APOBEC3, and tetherin, touching on both biological and molecular aspects of these restriction systems.