IL6 and infection: Multiple inflammatory cytokines, including TNF-α, IL-6, IL-1β, IFN-γ, IL-17, and VEGF, disrupt BBB and TJ integrity in BMECs (46, 50, 54–56), and inflammatory cytokine signaling at the BBB during infection facilitates leukocyte trafficking into the CNS, which is essential for the clearance of many pathogens (39, 41).