Interestingly, the presence of PR3- and MPO-ANCA have led to the differentiation of distinct disease phenotype of AAV: PR3-ANCA-associated vasculitis (PR3-AAV), MPO-ANCA-associated vasculitis (MPO-AAV), and ANCA-negative vasculitis. The gene discussed is PRTN3; the disease is anti-neutrophil cytoplasmic antibody-associated vasculitis.