The susceptibility loci identified suggest a further potential role of ustekizumab (IL-12/23 blockade) in ANCA -EGPA (associated with the IL12B susceptibility locus) cases or interferon I blockade in both ANCA-positive and negative EGPA (associated with the IRF1 susceptibility locus) [58]. Here, IRF1 is linked to eosinophilic granulomatosis with polyangiitis.