Through binding to IL-5 receptor α-chain (IL-5Rα), IL-5 promotes the proliferation, maturation, migration, survival, and activation of eosinophils.[7], [8], [9] Increased IL-5 levels were detected in EA10 and eosinophilia has been observed in IL-5 transgenic mice.11 The gene discussed is IL5; the disease is Increased total eosinophil count.