STING agonist-3 exhibits activation of STING in cells(pEC50 of 7.5), this assay is determined using a luciferase reporter assay in human embryonic kidney cells (HEK293T) co-transfected with plasmids expressing STING and the enzyme firefly luciferase driven by the interferon stimulated response element promoter.In FRET assay, STING agonist-3 exhibits a pIC50 value of 9.5 . This is a competition binding assay which aims to determine the binding potency of molecules to the C-terminal Domain (CTD) of human STING.