Background：

Interferon-inducible antiviral protein which plays a major role in the cell antiviral state induced by type I and type II interferon. Catalyzes the conversion of cytidine triphosphate (CTP to 3’-deoxy-3’，4’-didehydro-CTP (ddhCTP via a SAM-dependent radical mechanism. In turn， ddhCTP acts as a chain terminator for the RNA-dependent RNA polymerases from multiple viruses and directly inhibits viral replication. Therefore， inhibits a wide range of DNA and RNA viruses， including human cytomegalovirus (HCMV， hepatitis C virus (HCV， west Nile virus (WNV， dengue virus， sindbis virus， influenza A virus， sendai virus， vesicular stomatitis virus (VSV， zika virus， and human immunodeficiency virus (HIV-1. Promotes also TLR7 and TLR9-dependent production of IFN-beta production in plasmacytoid dendritic cells (pDCs by facilitating ’Lys-63’-linked ubiquitination of IRAK1 by TRAF6. Plays a role in CD4+ T-cells activation and differentiation. Facilitates T-cell receptor (TCR-mediated GATA3 a