mA is not the only RNA modification that can be found in viral RNAs. For instance, N,2-O-dimethyladenosine (mA) can be found in influenza and herpes simplex virus type 1, even though the effect this mark has on the life cycle of these viruses remains unknown. NAT10 mediated acetylation of cytidines on HIV-1 RNA was recently reported. Another modification commonly found in coronaviruses, flaviviruses and poxviruses (all of them are cytoplasmic viruses) is the 2-O-methylation of ribose moieties. The addition of this mark is catalyzed by a viral methyltransferase. 2-O-methylation binds to and inhibits Toll-like receptor 7 (TLR-7), which is involved in activating the production of inflammatory cytokines. Moreover, this modification enables viral RNAs to evade the antiviral actions of the IFIT proteins, a family of interferon-induced proteins that limit viral replication.