ISG20, an actor of the innate immune response

The interferon (IFN) system is a major effector of the innate immunity that allows time for the subsequent establishment of an adaptive immune response against wide-range pathogens. The effectiveness of IFN to control initial infection requires the cooperation between several pathways induced in the target cells. Recent studies that highlight the implication of the 3′–5′ exonuclease ISG20 (IFN Stimulated Gene product of 20 kDa) in the host's defenses against pathogens are summarised in this review.