The eosinophil major basic protein (MBP), a constituent of the eosinophil secondary granule, is implicated in cytotoxicity and mediation of allergic disorders such as asthma and the level of eosinophil MBP was reported to be high in biological fluids from patients with asthma and other eosinophil-associated disorders [12]. The gene discussed is MBP; the disease is asthma.