N4-acetylcytidine (N4A) is an organic compound and a metabolite of transferrable ribonucleic acid. Its molecular formula is C11H15N3O6. Preliminary studies suggest that N4A was mainly found on tRNA and 18S rRNA, while recent studies have shown that there is also a large amount of N4A on mRNA, whose abundance is not even lower than the m7G cap modification carried by mRNA (Arango et al., 2018). The generation of N4A is catalyzed by N-acetyltransferase 10 (NAT10) or its homologous enzyme. N4A is produced by acetylation in eukaryotic RNA and is the only human enzyme with both acetyltransferase and RNA binding activity (Arango et al., 2018).