NFKB1 and Salmonella Infections: Specific genes upregulated 12 hours post-challenge included caspase CASP4, which plays a key role in inflammasome-mediated immunity to Salmonella infections (22, 23); IFITM2, which can inhibit intracellular bacterial growth in monocytes (24); and RBCK1, a component of a complex regulating NF-kB pathway activation (25).