FCGR3B and microscopic polyangiitis: For example, FCGR3B low CN (<2) is associated with Granulomatosis with Polyangiitis (Wegener's Granulomatosis) and Microscopic Polyangiitis (antineutrophil cytoplasmic antibody-associated systemic vasculitidies) in one study [8], and high FCGR3B CN (>2) in another [7], and no association has been observed with vasculitis in conjunction with systemic lupus erythematosus [15].