Since multiple cytokines, including IL-4, IL-13, and IL-5, are involved in the eosinophilic type-2 inflammation, various molecular targeted drugs have been used in the treatment of patients with allergic or eosinophilic diseases and were introduced as a treatment modality for type-2 refractory disorders [12,13,27]. The gene discussed is IL5; the disease is eosinophil disorder.