STING1 and viral infectious disease: Moreover, immunohistochemistry analysis of lungs from SARS-CoV-2-infected mice showed specific signals of STING phosphorylation in the multinucleated cells by staining with the mouse-specific phospho-STINGSer365 antibody (Fig. 2i, indicated by the triangle), suggesting that STING is activated upon syncytia formation during viral infection in vivo.