In addition, and relating to the IL-22–mediated regulation of barrier function and vascular inflammation alluded to above, IL-1β was recently shown to act on endothelial cells to stimulate an NF-κB–independent, MyD88/ADP ribosylation factor (ARF) nucleotide binding site opener (ARNO)/ARF 6–dependent pathway of vascular permeability that contributes to vasculitis in autoimmune disease 65. This evidence concerns the gene MYD88 and vasculitis.