STING agonist 12b is an agonist of stimulator of interferon genes (STING).1It binds to STING (Kd= 26.4 μM) and induces interferon reporter gene expression in cells expressing human or mouse STING (EC50s = 7.45 and 10.23 μM, respectively). STING agonist 12b (40 μM) induces expression of TNF-a, IL-6, IP-10, and IL-1b in THP-1 cells.