STING1 and neoplasm: To test whether STING agonist and gemcitabine cooperated in controlling PDA growth, we treated KPC tumor-bearing mice with gemcitabine prior to administration of the murine STING agonist 5,6-Dimethyl-9-oxo-9H-xanthene-4-acetic acid (DMXAA) (Fig. 1a).