STING1 and neoplasm: To evaluate the role of host versus tumor cell STING expression on STING pathway activation, tumors from these experiments were assessed for expression of STING, pIRF3 (S396), and pTBK1 (S172) at 3 hours after treatment with TAK-676 2 mg/kg intravenously As shown in Fig. 5E (left), TAK-676 treatment induced expression of pIRF3 (S396) and pTBK1 (S172) in both WT and STING-deficient mice implanted with B16F10 WT tumors.