Similarly, WT Caco-2 cells pretreated with the caspase-1 inhibitor YVAD exhibited incomplete loss of IL-18 release after Δ6 Yptb infection compared to dimethylsulfoxide (DMSO) vehicle-treated cells (Fig. S2B), suggesting that caspase-1 contributes to, but is not absolutely required for, Δ6 Yptb-induced inflammasome activation. This evidence concerns the gene CASP1 and infection.