The European Vasculitis Genetics Consortium performed the first GWAS study in AAV that demonstrated distinct genetic differences between GPA and MPA, where HLA-DPB1 and HLA-DPA1 were associated with GPA, and HLA-DQB1 and HLA-DQA2 with MPA [19]. This evidence concerns the gene HLA-DPA1 and granulomatosis with polyangiitis.