Further, endothelial IL-1R1 is essential for endothelial activation in the context of IL-1-driven brain inflammation [44] and a further study using microglial-specific IL-1R1-deficient mice showed that IL-1 actions on brain endothelia triggers the production of endothelial-derived factors that are able to activate microglial cells [54]. Here, IL1B is linked to brain inflammatory disease.