ERBB2 and cancer: To test if type III IFNs are regulated by TBK1/IKK signaling similar to type I IFNs in response to STING agonism, we treated the cancer cell and PBMC co-cultures with the HER2 ADC with or without TBK1/IKKε inhibitor BX795 and measured IFNβ and IFNλ cytokine production.