MPO and ganglioneuroma: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an autoimmune disorder and characterized by relapsing and remitting necrotizing pauci-immune vasculitis that mainly affects kidneys and lungs.1,2 In case of kidney involvement, ANCA-associated glomerulonephritis (ANCA-GN) refers to AAV-induced kidney injury, which can be divided into myeloperoxidase (MPO)-ANCA-GN and proteinase-3 (PR3)-ANCA-GN.3 The treatment of patients with AAV is improving.