The phosphorylated IRFs translocate to the nucleus where they initiate the transcription of type I IFN. Of note, the C-terminal region of TRIF contains a receptor-interacting protein homotypic interaction motif (RHIM), which interacts with receptor-interacting serine/ threonine-protein kinase 1 (RIP1) to activate TRAF6 and results in the late phase activation of NF-jB and MAPKs