The recent meta-analysis demonstrated that PR3-ANCA has greater sensitivity than MPO-ANCA for GPA (74% vs. 11%), while MPO-ANCA has greater sensitivity for MPA (73% vs. 7%), with consistently high specificities of both types of ANCA (mean 97%; range 93–99%) (83). This evidence concerns the gene PRTN3 and microscopic polyangiitis.