Contrastingly, myeloperoxidase (MPO) and proteinase 3 (PR3) antibodies are features of ANCA-associated vasculitis (granulomatosis with polyangiitis, microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis) [5]. This evidence concerns the gene MPO and eosinophilic granulomatosis with polyangiitis.