Wild-type (WT) (B6.WT, black, n=13 for (A–E), and both co-housed B6.WT and B6.Nlrc4+/–Casp11+/–, black, n=9 for (F–O)), B6.Nlrc4–/–, and B6.Nlrc4–/–Casp11–/– mice were treated orally with 25 mg streptomycin sulfate in water and orally challenged the next day with 107 colony forming units (CFUs) of WT Shigella flexneri. In (A–E), B6.Nlrc4–/– mice received 200 μg of either TNFα neutralizing antibody (pink, n=13) or isotype control antibody (light blue, n=14) by intraperitoneal injection daily from 1 day before infection through sacrifice at 2 days post-infection. This evidence concerns the gene NLRC4 and infection.