NFKB1 and infection: Each mutant in this panel was deleted of a different effector gene (tir, map and espZ), a TTSS chaperone gene (cesF, cesT), or an entire pathogenicity island, as indicated, or other genes including eae (encoding intimin) and fliC. We performed infection assays using the above mutants and tested for p65 translocation to the nucleus and for induction of NF-κB-dependent expression.