As the absence of LytSR resulted in significant attenuation of GBS virulence, we examined the host immune response during sepsis by quantifying the levels of the proinflammatory cytokines IL-1β, IL-2, IL-6, IL-17A/F, MIP-3α, KC/GRO, and TNF-α in the serum of mice infected with the WT or ΔlytS strains. This evidence concerns the gene IL1B and Sepsis.