HEK293T cells were transfected with a firefly luciferase reporter plasmid encoding the IFN-β promoter plus a TK renilla plasmid and an increasing dose of flag-tagged MARCH2 plasmid (50, 100, 200, 400 ng) plus expression plasmids for TBK1 TRIF , for 24 h. Results are expressed relative to those of renilla luciferase alone (Internal control). 