Antineutrophil cytoplasmic antibody associated (ANCA) vasculitis, a group of rare, but life threatening, systemic diseases affecting small vessels, including those of vital organs, has been associated with high levels of circulating IL-16; in addition, circulating IL-16 levels correlated with disease damage (63). Here, IL16 is linked to anti-neutrophil cytoplasmic antibody-associated vasculitis.