MBD2 and viral infectious disease: We measured the expression of methyltransferases (METTL3, METTL14) and demethylases (FTO, ALKBH5), and found that the expression of FTO and ALKBH5 rather than METTL3 and METTL14 were gradually increased upon virus infection (Figure S4B, Supporting Information), which may account for that the m6A methylation of Mavs mRNA is decreased in virus‐induced macrophages (Figure 4B).