IFIH1 and viral infectious disease: The sumoylation of RIG-I at Lys96 and Lys888 and MDA5 at Lys43 and Lys865 was demonstrated to inhibit the degradation of RIG-I and MDA5 in the cell resting state and promote the PP1-mediated dephosphorylation of RIG-I and MDA5 during viral infection (Figure 2) [87].