NFKB1 and infection: The results showed that in RAW264.7 cells infected with dead E. tarda, phosphorylation of NF-κB p65 increased with time, while in RAW264.7 cells infected with live E. tarda, phosphorylation of NF-κB p65 was comparable during the course of infection and at each time point was apparently lower in level than that in dead E. tarda-infected cells (Figure 8).