The enterohemolysin gene (ehxA), present in all EHEC (49/49) and nearly all EPEC (12/13) strains in this study, encodes for a pore-forming toxin, which elicits in vivo production of IL-1β from human mononuclear cells, a commonly expressed cytokine during HUS infections [59]. The gene discussed is IL1B; the disease is hemolytic-uremic syndrome.