Reconstituting Sting−/− MEFs with human STING (WT) resulted in the induction of Ifnb and Il6, and phosphorylation of TBK1, IRF3 and p65 (NF-κB) on infection with herpes simplex virus-1 (HSV-1), a double-stranded DNA virus (Fig. 3a–c), whereas reconstituting the MEFs with human STING (C88/91S) failed to activate the type I interferon response. Here, STING1 is linked to infection.