We could also detect a higher prevalence of anti-KIF5C (aa 743–783) antibodies in MPA compared to GPA patients (39% vs. 10%, p = 0.0008), with the largest difference detected when comparing anti-MPO positive MPA patients vs. anti-PR3 positive GPA patients (45% vs. 11%, p = 0.0005). The gene discussed is MPO; the disease is microscopic polyangiitis.