1. Serum eotaxin-3 was highly elevated only in active EGPA (specificity: 87.5%, sensitivity: 98.6% at a cut-off level of 80 pg/ml). 2. None of the tested SNPs within the eotaxin-3 gene influenced the susceptibility to develop EGPA. The gene discussed is CCL26; the disease is eosinophilic granulomatosis with polyangiitis.