GDNF and eosinophilic granulomatosis with polyangiitis: 1. 12 out of 19 candidate markers were positively correlated with blood eosinophil count (FGF-7, SCF, GDNF, ß-NGF, IGFBP-4, Axl, PIGF, insulin, NT-4, ErbB3, OPN, BMP-4), while two, CD14 and MCP-3, were negatively correlated 2. The higher expression of Axl, OPN, HCC-4, GDNF, MCP-3 was found in active EGPA