m6A (N6-methyladenosine) is the most abundant internal modification in mammalian mRNA. This modification is installed by the m6A methyltransferases or termed writerssuch as METTL3 and METTL14, and can be reversed by demethylases that serve as erasers such as FTO and ALKBH5. The stability of m6A-modified mRNA is regulated by m6A reader protein YTHDFs, which recognizes m6A and reduces the stability of target transcripts. m6A modification and its regulatory proteins play critical roles in cancer pathogenesis and progression. m6A modification is also invovled in viruses life cycles, suggesting that drugs targets to m6A pathway could be used for antiviral thereapy.