TNF and infection: Like cytotoxic dose TNFα, polymicrobial infection induced comparable IKK activation in the livers of WT littermate and Bad−/− mice, but not in the livers of Tnf-R1−/− mice as expected (Fig. 6e), further suggesting that stimulation of the BAD pro-apoptotic activity by polymicrobial infection is not the result of defective IKK activation.