Interferon-induced antiviral exoribonuclease that acts on single-stranded RNA and also has minor activity towards single-stranded DNA. Exhibits antiviral activity against RNA viruses including hepatitis C virus (HCV, hepatitis A virus (HAV and yellow fever virus (YFV in an exonuclease-dependent manner. May also play additional roles in the maturation of snRNAs and rRNAs, and in ribosome biogenesis.,ISG20,CD25,HEM45,Epigenetics & Nuclear Signaling,Immunology & Inflammation,Cytokines,Interferons,Cell Intrinsic Innate Immunity Signaling Pathway,ISG20