Consistent with this observation, serum levels of TNF-α, IL-6, and HMGBI were also significantly higher in the CB2R deficient mice as compared with the WT control group at 3 hours after 5 mg/kg of LPS administration (Figures 1(b)–1(d)), indicating that the genetic deletion of CB2R resulted in increased susceptibility to infection. Here, IL6 is linked to infection.