As reviewed by Carlson et al.(10), three serologic profiles have beendescribed in levamisole-induced vasculitis: no circulating autoantibodies in those withorgan-limited disease, positive MPO and PR3 antibodies in patients with necrotizingsystemic vasculitis, or positive cANCA and PR3 antibodies in cocaine-induced midlinedestructive lesions. The gene discussed is MPO; the disease is glycogen storage disease VI.