A study has identified novel biomarkers that distinguish between active antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and remission. Monach et al. measured levels of 28 serum proteins in patients before and 6 months after treatment in a large clinical trial of AAV. Data from the 137 patients in remission at month 6 showed that levels of 24 of the biomarkers were significantly different to levels at screening. CXCL13, MMP-3 and TIMP-1 were the biomarkers that best discriminated between active disease and remission.