Dephosphorylation of MDA5 and RIG-I is a key step of their activation [37, 45, 46]. To test whether DHX29 is required for MDA5 activation, we used wildtype, non-interacting (DHX29c) and inactive (WAM-DHX29 and WBM-DHX29) form of DHX29 to test the phosphorylation level of MDA5 and RIG-I. However, we did not detect any significant change in phosphorylation of RIG-I and MDA5 with different forms of DHX29 in the presence or the absence of stimulation (S6E and S6F Fig).